Texas82GP's GMT900

Texas82GP

Just-a-worm
Apr 3, 2015
7,981
18,676
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Spring, Texas
For those still interested in the glacially slow transmission swap thread, I worked on the truck all weekend. No, it's not done but significant progress was made.

Friday:
Friday was a paid holiday so my plan was to work on the truck. My brother took the day off. He had some stuff to do but came over to the storage late that morning because he wanted to help. I'm really lucky to have him. I started out with putting the new cooler fittings in the transmission. I went with inverted flare fittings instead of the GM quick connect fittings or fittings for AN hose. The front fitting is for a 4L60E or 4L80E. It went in with no drama. The rear fitting is 4L80E specific in that it has the 'pipe' on the end of it that extends into the transmission presumably to direct the returning fluid onto parts that need lubrication. The rear fitting wouldn't start. I started out with a thread file tying to give the first few threads better definition. No luck. Two trips to ACE Hardware later (because I wasn't smart enough to buy the right die nut the first time) and I had the correct die nut. I hoped to just clean up the first few threads but it didn't work out that way I ended up cutting a lot of metal but in the end I had some pretty good looking threads. Once I had it threaded in a ways it started to stiffen up a little but I didn't use Teflon tape so I wasn't overly concerned. I was unsure of how far to go since the rear fitting has an O-Ring. I wanted to crush the O-Ring enough to seal but not kill it. I was pretty careful so I hope I got it right. Next I cleaned up and installed the two speed sensors, their brackets and bolts. Somewhere in there, Sean showed up and brought me some Vaseline, which the builder recommended I use on the O-Ring on the input shaft for the torque converter lock-up. I didn't have any transmission assembly gel and said to use the Vaseline instead of buying assembly gel. I used that and installed the torque converter. I didn't put any fluid in the converter, per the builder's recommendation. He said it wasn't necessary. The last time I tried to put fluid in the converter, I didn't get much in it and poured a good bit of it out when I stood the converter up to install it. Next, Sean helped me get the transmission on the jack and get it strapped down. Here it is, ready to go in....

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Next, I got under the truck and blew two more cans of cooler clean through the lines and transmission coolers. Then I followed with compressed air. The system is clean now. Since the lines needed to come out for modification, I went ahead and pulled them then to get them out of the way. I really don't like fighting with those GM push lock fittings. It's fine if you have good access but if you don't it sucks. After some struggling and getting frustrated, we ended up pulling the grill and bumper cover to get better access to the auxiliary transmission cooler. We got it and the lines pulled....

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The upper transmission line (transmission to radiator) was leaking at the rubber hose so I ordered up a replacement...

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I think at this point we went back to the house and ate lunch. When we went back, we were finally ready to go in with the transmission. It went in without much difficulty. We got all the bellhousing studs torqued and also got the transmission vent bracket, transmission dipstick, and fuel line bracket all secured to their respective studs with the lock nuts. Access to some of that is not great but I have about a 36" long extension that really helps. We got the transmission jacked up and put in the crossmember.....

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I've long suspected having a bad motor mount or bad mounts. Right at a year ago I bought some custom fabbed mounts with polyurethane bushings from a little shop in Alabama that specializes in custom stuff for GMT 400, 800 and 900 trucks. I just hadn't had time to put them in. With the vehicle this far apart, I decided now was the time. It was late afternoon by then so Sean started picking up tools and picking up the shop. I dove right in to pulling the driver's side motor mount. I got all the bolts out but we couldn't get the mount out from between the frame and the block. We had the engine jacked up pretty high. I was worried about crushing the intake manifold under the cowl so we stopped there.....

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Saturday:
We started our Saturday like we always do by going to breakfast with Dad. Afterwards, Dad and Sean were helping our Sister by moving some furniture that came from my niece over to her (my Sister's) house for her little girl. The bed frame needed a little TLC when they put it together so they were tied up for the day.

I decided the header was going to have to come out to get the motor mount out. I decided that since I was going to have to pull the spark plugs and had to pick up exhaust manifold gaskets, that I would go ahead and pick up a new set of plugs. I had to go to three auto parts stores to get a set of AC Delco spark plugs for a 5.3! Ridiculous. Once I was done with my boondoggle, I realized I didn't have what I needed to gap the plugs at the storage so I went home and gapped them.....

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I posted the pic above because I wanted to show the AC gap tool. I find the scale is not very accurate but the "C" is a great tool to use as a hook to open up the gap a little bit. It's a great tool in my opinion. I've had it for like 20 years now.

After gapping the plugs I headed back to the storage. I got started by pulling the Driver's front wheel and wheel well. Then I pulled the plug wires and plugs. Then I removed the header. The motor mount came right out at that point....

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I'm going to have to stop here as I have to get back to it, here at the office. I'll finish the update either tonight or at lunch tomorrow. Until then, thanks for following along.

Best,

Jared
 
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JAMCAR223

Royal Smart Person
Jun 6, 2014
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Houston, TX.
'Bout time to wrap this up, and put some time and money into the Grand Prix. I'm giving you 1.5 years to get the car ready for Cruisin' the Coast 2020. Sean's Camaro, Dad's Galaxie, Your Grand Prix, and my Cutlass Aero. (GN on standby). Let's do this!
 
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Texas82GP

Just-a-worm
Apr 3, 2015
7,981
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Spring, Texas
'Bout time to wrap this up, and put some time and money into the Grand Prix. I'm giving you 1.5 years to get the car ready for Cruisin' the Coast 2020. Sean's Camaro, Dad's Galaxie, Your Grand Prix, and my Cutlass Aero. (GN on standby). Let's do this!
That sounds fun James. I hope it happens.
 
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Gonzo1970

G-Body Guru
Sep 30, 2018
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Purty! well done!

-Gonz
 
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Texas82GP

Just-a-worm
Apr 3, 2015
7,981
18,676
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Spring, Texas
Ok, back to the update. Sorry for the break. The update was too lengthy for my lunch hour. When I left off, I had just pulled the driver's side motor mount. It turned out to be bad after all.....

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In went the new motor mount with really no drama...

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I torqued all the bolts and then moved on to putting the header back in. First, I put some paper towels in the exhaust ports and put the old spark plugs back in the heads. Then I scraped the surface of the head clean with a razor scraper. Next I put some fresh anti-seize on the header bolts. I wanted to say, I'm disappointed with how poorly the black finish of the ARP head bolts has held up (hasn't at all) but am really happy with how the stainless ARP header bolts have held up. I used Fel Pro manifold gaskets. They had hooks on each end of the gasket so I could hang the header by the front and rear bolt and then slip the gasket in. It made it a lot easier since I was doing this by myself. I got the header torqued. I put anti-seize on the new plugs and put them in. I torqued them (11 ft. lbs.). I cleaned up the plug wires and put fresh dielectric grease in the boots. They went back on. Then, I turned my attention to more crispy convoluted tubing. The repair required the fourth run to the auto parts store of the day (first three were at the beginning of the day to buy Delco spark plugs for a 5.3 - ridiculous!)…...

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Then I went back in with the wheel well, followed by the wheel. Next I pulled all the mats out from under and around the truck and swept and vacuumed under it. While I was under the truck I thought to check the alignment of the transmission mount with the slot in the crossmember. It was out of alignment. Uh oh. Maybe I shouldn't have torqued everything and buttoned everything up on the driver's side. Oh, well, press forward. After I got done cleaning up, I got the truck down off the stands. I pulled the front of the truck over to get the passenger front fender away from the wall in anticipation of doing the passenger side motor mount. Then I jacked the truck back up and put it back on stands......
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By then it was past 6 PM and I was out of gas. My brother was also texting me, urging me to come home and eat dinner and watch the Astros game with him. It was a pretty good Saturday.

Sunday:
Full disclosure: I'm a soft fatty. I was pretty stiff and sore Sunday morning. I didn't really want to go work on the truck but I felt I had to press forward. My brother, sister-in-law and the kids went to East Texas to see some of her family for Easter. Dad's side of the family wasn't doing anything that I was invited to so I went ahead and pressed on. I had to finish my laundry first so I didn't get over to the storage until about 9:30 AM. I started by pulling the wheel and the wheel well on the passenger side. Instead of diving right into spark plug and header removal, I elected to first address yet more crispy convoluted tubing.....

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The reason being, I wanted to get all of the crispy plastic rain behind me all at once rather than slowly knock it off while working on the motor mount and end up spending the whole time wallowing around in it. Here is the aftermath of pulling the cooked stuff....

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I guess the headers are cooking this stuff. I already replaced a bunch of it on the top of the engine the last time I had the intake off. I think some of it is just lousy material. I kind of wish I had started going back with Power Braid or something like that instead of convoluted tubing but at this point, I'm just going to keep chasing the crispy stuff as needed. After I got that mess all cleaned up, I went ahead and made the repairs....

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I had some Summit Racing brand Velcro-on heat shield for the Grand Prix. I ended up using a foot or so of it for the hot cable to the starter. It might not fit in the clip on the frame now. We'll see.

Next, I pulled the spark plug wires, spark plugs, engine oil dipstick tube and header. Then out came the passenger side motor mount. It hadn't failed but had some dry rot on it. Then I moved forward with putting in the aftermarket motor mount. It was a fight getting it lined up. I ended up breaking all the bolts loose on the driver's side mount, which wasn't easy with it all put back together. With patience and some brute force (pushing the rear of the transmission tailhousing over with my foot), I got the power team pretty well lined up and got all the bolts in on the passenger side.....
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The bolt hole in the transmission mount is now in the slot on the crossmember. It isn't perfectly centered, but the bolt will thread right in. I'm probably going to use a small ratcheting strap to pull it over the final 1/8" or so to center it and the tighten that bolt down. Then I'll torque both motor mounts.

By then it was 2:00 PM and I didn't stop for lunch or anything. I was pretty well out of gas and I needed to go home and take care of the dogs. That was my excuse to roll everything up and go home. Moving forward I think I can get both mounts torqued, get the passenger header, spark plugs, plug wires, dipstick tube, wheel well and wheel all buttoned up next Saturday. Then I'm going to move to modifying the transmission lines and installing the new oversized transmission cooler. Then I will just focus on putting everything back together and finishing the transmission install. I'm guessing I have two weekends left of work before I have it all back together.

That reminds me, I wanted to ask you guys about the clearance between the torque converter and the flexplate. When I put the converter on the transmission, I turned it while pushing back on it to make sure it was fully engaged. The converter is essentially as far back as it will go. Right now, there is about 1/8" of clearance between the converter and the flexplate….

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Normally, I would just pull the converter up to the flexplate with the bolts. I only recently became aware that there is something to this clearance and you can't take for granted that it is right when you are running an aftermarket setup. Also, the bolts that I got from Circle D came with washers or shims of a few different thicknesses. My research indicates the 1/8" clearance is about ideal and I'm good to just pull the converter forward to the flexplate with the bolts. My research says I don't need to use any shims. Is that right?

That's it for now guys. Let me know what you think on those shims as I hope I'll be ready to install the torque converter bolts next weekend. Thanks for the interest and the feedback. I appreciate it. Until the next update.....

Best,

Jared
 
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Texas82GP

Just-a-worm
Apr 3, 2015
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I made some good progress on the swap this past weekend. I started Saturday morning with setting up a ratcheting strap to pull the tailhousing of the transmission over to the passenger side about an 1/8", I could get it to move by hand but couldn't hold it and tighten the bolt into the transmission mount at the same time. I only took a picture because it took me so long to get the strap setup correctly....

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The strap pulled the mount in to perfect alignment with the slot in the crossmember with ease. I went ahead and torqued the transmission mount bolt, then torqued the bolts from both motor mounts into the engine block. Then I torqued the bolts from the motor mounts into the frame. Finally, I torqued the cross bolts, which are running through polyurethane bushings. I figure slight misalignment with the bushings cased the drivetrain to shift slightly. Torqueing the fasteners on the driver's side wasn't all that much fun with it all put together. My 3/8" universal joint didn't like the 50 ft, lb. load I was repeatedly putting on it either but I got it done.

With that done, I moved on to reinstalling the passenger side header, spark plugs, and spark plug wires. I also replaced the convoluted tubing on the battery cable from the fusible link on the firewall to the back of the alternator. Then I turned my attention to the installation of the larger aftermarket transmission cooler and modifying the transmission lines to suit it and the 4L85E. I started with pulling the hood latch and the grille support bracket to make room for the transmission cooler......

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I bought some aftermarket brackets designed to bolt one of these transmission coolers into a GMT900. The upper bracket worked well. The lower, not so much. I ended up not using the lower bracket and just notched the bottom of the "A" frame of the core support to make room for the lower mounting tabs of the transmission cooler and the driver's side connection on the cooler. With the cooler bolted up, I loosely reinstalled the grill support bracket to see if this was going to work or not......

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It actually fit in there pretty decent. Obviously this transmission line isn't going to work though....

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By then it was past 6 PM and I'd had enough for the day. Sunday morning I got over to the storage around 8. I started with pulling the transmission line pictured above to modify it. It runs from the upper port of the transmission cooler in the radiator to the passenger side port (inlet) of the auxiliary cooler. Since I have the tools to do it, I decided to just cut and flare the lines to modify them. With this particular line, I chose to cut it on a nice straight run under the core support....

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Then flared it with my hydraulic flaring tool. I bought this years ago to make lines with the GM quick connect type fitting. It's a great tool....

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Here's the stock transmission line with a new double flare....

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Then I did some cutting, bending and flaring to make a line to bridge the gap between under the core support to the inlet on the auxiliary cooler...

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Texas82GP

Just-a-worm
Apr 3, 2015
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Spring, Texas
I used inverter flare unions to tie the two new pieces together. I realize this is a somewhat unorthodox approach but my thinking was this is way more affordable than AN hoses, Is way better than rubber hose and I already had the tools and knowledge to do it this way. I considered buying all new lines for a GMT800 with a 4L80E but they would have to be modified for the larger transmission cooler anyway and I didn't know how well the rest would fit so, this is the way I went....

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Here's a look at the same junction from the fan side...

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And here is the cooler side of the 'patch'....

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With that done, I cut and flared both ends of the line that runs from the auxiliary cooler to the transmission and hung it in its clips under the truck. Then I made up a section of line to connect it to the auxiliary cooler....

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The last line runs from the transmission to the top fitting for the transmission cooler in the radiator. I stayed with the quick connect fittings in the radiator for both lines but I did pull both fittings and replace the o-rings and clips with new ones. I had bought a replacement for this last line since the hose on mine was leaking. I cut the rearward end off of this new line, roughly in the vicinity of the front of the bellhousing. At this point, I just needed to bridge the gap between the back of the block and the ports on the transmission to be done with the lines. More bending, cutting and flaring....

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It's hard to get a real good picture of the lines up there in the tunnel. Here are a few more pics....

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And here is a look at where the lines junction into the stock lines...
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If I had it to do over again, I'd like the junction on the upper line to be further forward and the one on the lower line to be further rearward but they aren't bad to get wrenches on, especially with the passenger wheel and wheel well out (not a big deal to pull on these trucks). Overall, I've very happy with how the transmission lines turned out.

To be continued......
 
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Texas82GP

Just-a-worm
Apr 3, 2015
7,981
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Spring, Texas
With the transmission lines done, I pulled the auxiliary cooler so I could blow some paint on the bare metal where I trimmed the lower brace of the "A" bracket on the core support. I used some VHT Chassis and Rollbar paint as it was what I had on hand and I like this stuff. Being epoxy based, it doesn't require primer. I managed to be patient and do a few mist coats and not pile the paint on there so it turned out fine....
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About a half hour later, I put it all back together, relocated the ambient air temperature sensor and rerouted the wiring for the hood latch sensor....

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With that done, admittedly, I started to piddle. I replaced the convoluted tubing on the battery cable that runs across the top of the firewall from the fusible link on the passenger side to the fuse and relay center on the driver's side. I also replaced some on the knock sensor wiring on the driver's side of the block. I think I'm done replacing convoluted tubing for now. I also glued the magnet out of the stock 4L85E pan into the aftermarket deep, cast aluminum pan. Finally I reinstalled the MAF and snorkel tube and put the engine cover back on....

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At that point, it was a little past 4PM so I picked everything up, locked up and headed home. I think I will have it all back together next weekend. At this point, I'm sweating the tuning more than anything because I'm afraid I waited to long to get on it. I managed to talk IT into installing EFI Live on my PC at work last Friday. I brought the AutoCal handheld in today and updated the firmware on it and made sure it was empty. The next thing I need to do is to copy the current tune in the truck to the AutoCal so I can send it to the tuner and request he make the necessary changes. I'm going to head to the storage as soon as I post this and work on doing just that. I'm guessing I won't have the tune for next weekend, though. I think by the end of next Saturday it will be mostly back together. I'm confident it will be back together on Sunday.

That's it for now gents. As always, thanks for the comments, the likes and for following along. I'll update when there is more progress to report. Until then....

Best,

Jared
 
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motorheadmike

Geezer
Nov 18, 2009
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I am slow clapping (in appreciation) the hell out of those hard lines.
 
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