EL CAMINO Clunking auto trans under load when warm and low rpm

CopperNick

Royal Smart Person
Supporting Member
Feb 20, 2018
2,250
113
Canada
To me soft and sluggish means that the TV cable is still not adjusted properly. Somewhere on this forum there exists a fairly complete set of instructions on how to adjust that cable. There are also several you-boob videos outlining the same/similar methodology. The reason that i know the how of it is around here is that I posted them back in the late summer. The on site search engine should be able to turn them up for you to review.
 
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schwim

Not-quite-so-new-guy
Thread starter
Nov 13, 2022
15
3
Coastal VA, US
To me soft and sluggish means that the TV cable is still not adjusted properly.
From your lips to God's ears. I'm going to try that first to see what happens. I suspect it will solve the soft shift issue but I'll still have the psychotic back-and-forth shifting as I think that's going to be a different issue. As for the video, I planned on using this adjustment method described in a shift kit installation video I found during those searches.
 

JimmyD

Not-quite-so-new-guy
Feb 16, 2021
18
3
Umatilla, Florida
Understandable as some shops can go as high as 3k or more.

I can offer to help you with a good rebuilt one, I have several 2004r units.

The accumulator springs break all the time. It's a common problem. Also at that age and even if it had 1k on the clock, most likely the piston and other seals are no good just due to age.
Hello, fellow El Camino owner here. Would you be interested in letting go of one of your 200/4r transmission's ? I'm currently in the process of building a 383 for mine and would like to ditch the T350 in it for a 200. Much better gear ratios in the 200 than the 700. Thanks
 

78Delta88

Master Mechanic
Supporting Member
May 23, 2022
385
43
SW Arizona
Hello, fellow El Camino owner here. Would you be interested in letting go of one of your 200/4r transmission's ? I'm currently in the process of building a 383 for mine and would like to ditch the T350 in it for a 200. Much better gear ratios in the 200 than the 700. Thanks
I'll PM, ...Sure, what's the time frame? I'll go through it first, make sure clutches and seals are good.
 

schwim

Not-quite-so-new-guy
Thread starter
Nov 13, 2022
15
3
Coastal VA, US
Hey guys, a quick question. I've not gotten a chance to test pressures yet but I adjusted the tv cable and a short test drive resulted in only one remaining issue. On light to medium acceleration, there is a lag and rev between 2 and 3. On heavier acceleration, the shift is better.

I know pressure testing is the next step, I'm just curious what this sounds like. Is there a particular part or system that handles this shift that could be the culprit here? All other shifts are unaffected.
 

L05edSS

Not-quite-so-new-guy
Nov 29, 2022
21
3
Hello there!

87 with 305 and overdrive auto

I haven't owned an auto trans vehicle in over 20 years so I'm a bit rusty, forgive me.

This new-to-me 87 has an issue where when the vehicle warms up, it's got a jerking issue, as if the trans is completely disengaging and re-engaging rather violently, not softly, sort of like a repeating clunk. As soon as I give it a bit more gas, it goes away and the trans seems to behave like normal. I've checked the fluid and it's not burnt smelling and it's a bit above the full mark when warm and running. I've no record of previous services/repairs.

What should my first step be in diagnosing the issue? Any known problems that I should look at first?

Thanks for your time!
my guess is the TCC solenoid causing premature lock up. if the car shakes as if you let off a clutch wrong and it bucks some i've had that and didn't get it resolved before totaling it.but when i got my current monte back from a engine change went non ECM with a B&M lockup kit i got the same sound & sort of effect i recall on my last monte when had it in D and it locked/released rapidly at a low speed and sounded lik a hammer hitting something metal. converter shouldn't be locking in any gear except OD. also that transmission was a fresh rebuild with all goodies in it. pressure, i had a pressure gauge in the dash and don't recall any change and a local trans mechanic it stumped him.
 
Last edited:

schwim

Not-quite-so-new-guy
Thread starter
Nov 13, 2022
15
3
Coastal VA, US
my guess is the TCC solenoid causing premature lock up. if the car shakes as if you let off a clutch wrong and it bucks some i've had that and didn't get it resolved before totaling it.but when i got my current monte back from a engine change went non ECM with a B&M lockup kit i got the same sound & sort of effect i recall on my last monte when had it in D and it locked/released rapidly at a low speed and sounded lik a hammer hitting something metal. converter shouldn't be locking in any gear except OD. also that transmission was a fresh rebuild with all goodies in it. pressure, i had a pressure gauge in the dash and don't recall any change and a local trans mechanic it stumped him.
Thanks for the ideas. As noted above though, the situation has changed somewhat after adjusting the tv cable myself. I'm not experiencing the clunking and shifting back and forth right now, I'm just dealing with a very slow and unsure shift from 2 to 3. It goes out of 2, revs as if in neutral then slowly and softly moves into 3.

I'm wondering if there's a particular system that handles that shift that would be the primary suspect. Any thoughts on it would be most welcome.
 

ELCAM

G-Body Guru
Jun 19, 2021
712
93
For your latest symptoms.
1.jpg

2.jpg


From the ATSG. These are your possible problems.
The blue requires pulling the pan.
Yellow requires pulling the pan and valve body.
Orange requires pulling the intermediate servo on the out side of the case.
Red requires a complete teardown of the transmission.

Let's start with pulling the pan. There will be very fine metal powder in the bottom of the pan. This is normal wear, if there are bigger grains of metal or any large peices like clutch material it needs to be rebuilt. You don't need to go further.
If the pan crud looks ok then check for TV cable, bellcrank and valve operation. Make sure everything works smoothly and that the valves in the valvebody all move full travel and the springs are doing what they should.

200-4R valve body TV.jpg


If everything with the TV cable looks ok i would put a few bolts back in the pan, jack up the transmission and remove the crossmember, remove the distributor cap so you do not break it and lower the transmission down as far as it will go so you can remove the intermediate servo cover. Once you take this apart you will need new seals for it. Numbers 17,18,20 and 22 in the diagram. Inspect the seals before you remove them for any damage so you can see if you found the source of the problem.
Look closely at the orientation of the lip seals so you can install the new seals properly. Lubricate with Vaseline and reassemble.
200-4R Int Servo.jpg

If you found a damaged seal reassemble and try it out. If no obvious signs of damage were found put the transmission back on the crossmember and remove the pan and remove the valvebody. Check the torque on the center support, use a 3/8 torque wrench torque to 18 foot pounds or 215 inch pounds.

support bolts.jpg

Use no sealer on the valve body gasket, clean everything completly there can be no garket material left anywhere. Do not scar or damage the alumnum case sealing surface. Install the check balls using a lot of vaseline to hold them in place and reinstall the valve body.

If none of those are the problem you will need to have the transmission rebuilt.
 
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