1990 C1500 700r4 Not shifting past second gear.

[uzgaro]

A quick Google search yielded this, not sure if it's what you're asking for exactly but might be helpful.

http://www.1990suburban.com/repair_...ssion_Principles_of_Operation_2nd_Edition.pdf

Thanks for that I appreciate it! I’m gonna take a look at it! Might replace the external parts that I can such as the governor and servo and tv cable. If those don’t check out I’ll look into rebuilding it.


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[HotrodZ06]

Most likely the 3-4 clutches are worn enough they won't engage. I would inspect the TV cable and try adjusting it if that doesn't work will probably need a rebuild. I am in the middle of rebuilding the 4l60 in a 2000 Escalade I picked up that suffered from burnt up 3-4 clutches.

 

[Erik the Awful]

A quick Google search yielded this, not sure if it's what you're asking for exactly but might be helpful.

http://www.1990suburban.com/repair_...ssion_Principles_of_Operation_2nd_Edition.pdf

Thanks! I'll look through that today.

 

[Erik the Awful]

Finally skimmed through it. There's no apply chart, but pages 73-81 give you the info you need to open up a spreadsheet and make your own apply chart. That said, the devil's in the details.

If the transmission makes the 1-2 shift, the governor is likely not the problem.

According to the apply chart I made, the 2-4 servo shifts the transmission into second, but isn't required for third gear. BUT! If you read page 45, the 2-4 servo has to receive release pressure to allow the shift into 3rd.

So, it could be your servo. It could be your 2-3 shift valvetrain. It could be your 3-4 clutch.

If you're thinking about swapping in a Corvette servo and your fluid looks good, it might be worth a shot. If you want to rebuild, or you've been towing a lot, or you have trash in your fluid, rebuild it.

** NOTE **
I can read the manual, but I've only ever rebuilt one TH700R4, and that was in a transmission class.