Manual swap

[Regular Guy with an Elky]

Hi I’m looking for some help. I am thinking about swapping out my auto for a 4speed in my 83 el Camino . I think a 3 groove Saginaw might work with my rear end it’s a 2.41. My confusion at the moment is the type of shifter and mounting kit . There is like a million choices . I want to keep my bench seat. Any thoughts would be appreciated . Thanks!

 

[Froh]

Definitely mount the shifter on the floor of the body. Putting it on the side of the transmission will result in incessant rattling, no matter how smooth the engine is. Since you might sometimes have a short driver, put it far enough forward for the seat to go to its farthest forward position. Get an acetylene torch and braze together , i.e. fabricate, the necessary linkage.

Your gear ratios sound good to me. With a 3.50X2.41 you will have a nice first gear; not so high that it requires excessive slipping of the clutch, but not so low that you need to shift up as soon as you get moving. A 2.41 axle will give good mileage on the highway.

The GM floor shifter from the donor car would be a good choice.

 

[CopperNick]

The biggest con against floor mounting the shifter to the drive shaft tunnel as was done by the factory for the Muncie shifters is that, under heavy acceleration, the shifter linkages can bind or hang as the engine is both accelerating and twisting in its mounts due to the torque that it is experiencing.

Not going to argue about whether a transmission mounted shifter will rattle or not. To me a rattle means something is either loose or has something else hitting it. The aforementioned rattle could have been as much a case of the shifter hitting the tunnel for some reason as due to physically shaking. If the shifter is shaking, then the engine is running and the shake is a reflection of the idle. However, if you grab the stick and the shifter mechanism itself is moving around, then you need to pay a visit to the bolts that mount the attaching plate to the tail shaft housing as well as to those that attach the shifter to the mounting plate.

One other argument against the tunnel mount is that the factory tried to solve the problem by using soft bushings in the levers to see if they would deflect enough to allow the throws from gear to gear to still work under WOT or near WOT acceleration. The result was mostly a "Bleah" response.





Nick

 

[pagrunt]

The only GM platform that I know of to use a floor pan/body mounted shifter was the '71-'80 H-body (Vega, Monza & clones) & the shifter rods were slotted to allow movement. Everything else with a Saginaw, Muncie or any other "side loaded" case transmission GM used the shifter is mounted to the side. Even the odd '68-'72 A-body shifter was mounted t the side along with the crossmember mount points. Part of the allure of the manual is seeing that slight movement of the stick as the engine natually rolls with the mashing of the fun pedal. But regardless, as the ITM shifters aged they got looser from wear & will shake. A well used Hurst will too but not as bad.

 

[Froh]

Hmmm, some interesting, and good, comments concerning floor mounted shifters.

The rattle I refer to is from the shifter itself. Every shifter has to have some clearance between the parts, some more than others.

Also, stick drivers, remember not to push sideways on the shifter as you come out of a gear. This causes unnecessary wear on the shifter. Some day when the wear is bad enough, you will push the lever to neutral, the lever will prematurely release the lower lever, the transmission will slip back into gear and there you sit with the shifter stuck in neutral and the transmission in gear. Very common problem. No amount of tugging will help. You will need to stop in a level area, and with no pressure on the gears, slide under the car and push the transmission lever back to neutral. Push sideways only when in neutral.

 

[Bonnewagon]

the only way they knew was to lower RPM via final drive ratio apparently

That is why they came up with the 3:50 to 1 first gear trans. Overdrives were still a few years away and that is the best way to use a granny rear by having a deep first gear. I still use that logic.

Saginaw with a flat side tail housing

Thanks, I forgot about that. I banged my head for a while once, before noticing the difference from the round tail housing.

Bonnewagon will know to whom I'm referring.

Speed Direct makes the spherical rod end linkage. It is absolutely better than the stock stuff that wears out fast. https://www.speeddirect.com/clutch-linkage

As for body mounting the shifter, I had a 1967 Firebird that mounted the 3 speed shifter to the rear transmission cross member. It sucked big time. Even with the sloppy rubber bushings, under a load, it was hard to get a smooth shift. As soon as I upgraded to a trans mounted Hurst competition plus, all was well.

As far as strength, fit the punishment to the crime. Trying to push a dead rear with a strong motor will kill the trans or the rear, or both. I ran a Pontiac 400 and a 3;11 to 1 Saginaw for many years with no issues. But the 3:23 rear gear took the strain off the parts and I had zero problems.

Under heavy use the arms will bend.

The factory spot welds are a joke. I take a big washer that fits on the Z-bar and weld it to the arm and the bar. That makes it very strong. At the very least I beef up the welds with an acetylene torch and make sure the entire arm end is solid to the bar. Just strip down the bar and clean the grease out first.

 

[CopperNick]

Just as an example, this is what I did with the G-body Z-bar that is now installed in my Monte. This shot shows it clamped into the vise in a vertical position only because I had to touch up the paint and needed to gin up a portable paint booth for the job.

That aside you can still clearly see the braces that I fabricated from light angle iron and then welded into place. The upper angle at which each brace meets its arm is as high up the arm as possible to provide the most stiffness while leaving room for the upper and lower rods to move freely. Bonnewagons use of that oversize washer as a re-inforcement is both slick and easy to add. I went a little more industrial with mine just because of what I had available to me to use and because I could. My ride is not and never will be a 100 point restoration so what someone else thinks of my "improvements" mostly means bupkus to me.



Nick


Nick

 

[Mighty]

There’s the factory saginaw and shifter from my 79 wagon the day I took it out of the car. Now a super t10 sits in its place along with the shifter that member gnvair made to use the original hole in the floor along with the bench seat. All of the advice given so far has been spot on. I fell into the worn hole doing the swap and before long I had replaced all of the worn out pedal linkages and the zbar and welded supports to it etc. I’ve had a spare factory manual trans column laying around for years because someone tried to steal my car about 20 years ago and they busted my column all to hell. Problem is, the one in the car is factory tilt so the spare I have doesn’t help me much since it’s non tilt.

 

[Bonnewagon]

I fabricated from light angle iron and then welded into place

That looks quite strong. Every car is different and clearance is always the determining factor for what works best. Bottom line is that the factory Z-bar needs help. I am using a stock 301 diaphragm clutch right now that doesn't put a lot of strain on the parts. But when I had a 400 in the Malibu wagon, I was using a RAM B&B clutch. On that type the effort increases the more you apply the pedal. That is what caused the factory welds to fail.

 

[Regular Guy with an Elky]

View attachment 247184
I am using the 3:50 first gear Saginaw in my Bonnewagon. It has a Pontiac 301, 3:23 rear, and works quite well. The only way to keep your bench seat is to use the factory shifter and mount. It positions the shifter about six inches forward so it clears the dash and bench seat. A 2:41 rear is about the worst rear they used in our cars. It is great for highway mileage with low rpm. But it is very hard to get any sort of acceleration with those gears. The 3:50 first gear times the 2:41 rear gets you only 8.4 to 1 overall ratio. You will still be riding the clutch a bit to get going. My old 1981 Malibu wagon came with a 3:50 first gear three speed Saginaw, 2:41 rear. Just horrible gear spread. A 3:11 first gear 4 speed Saginaw with a 3:23 rear was much better. A 3:08 rear with that 3:50 4 speed trans would be nice too. This is the shifter and installation kit. See the special shifter mount at the top.

Thanks for the info any idea where I can get those parts? Looks like they are not making the linkage anymore

 

[Regular Guy with an Elky]

There’s the factory saginaw and shifter from my 79 wagon the day I took it out of the car. Now a super t10 sits in its place along with the shifter that member gnvair made to use the original hole in the floor along with the bench seat. All of the advice given so far has been spot on. I fell into the worn hole doing the swap and before long I had replaced all of the worn out pedal linkages and the zbar and welded supports to it etc. I’ve had a spare factory manual trans column laying around for years because someone tried to steal my car about 20 years ago and they busted my column all to hell. Problem is, the one in the car is factory tilt so the spare I have doesn’t help me much since it’s non tilt.
View attachment 247268

Do you still have that shifter and install kit and is it for sale