I’m stumped on this one folks… I’ve thrashed Th350’s and Th400’s but this is the wife’s 92 suburban and I’m not even sure what the tranny is… the pan’s square. I thought it felt like the vacuum hose or modulator had sprung a leak but there ain’t one there! I drove it last weekend and thought I noticed a late shift or two but I forgot to check into it later. The wife says she hasn’t had a problem with it. I jumped into it tonight and it wouldn’t upshift from second. I had it in OD and dropped it to D, it downshifted hard and loud. I stopped and tried to run through the gears manually. Now whatever gear I have it in, it won’t upshift untill I hit 4000 rpm. It was a little low on fluid and I topped it off, but it’s not leaking and that made no difference. Any ideas or sugestions? And how much more complicated is this tranny to thrash than a TH400? I made my own holding jig and spring compressor for the old trannys but I’ve got a feeling I’m gonna have to buy some real tools…

Since you checked the fluid this probably isn't the problem, but have you checked your radiator for "strawberry milkshake". A friend of mine's 700 sprung a cooler leak not too long ago and had similar symptoms once it got warmed up.

As far as rebuilding, there are a few nice to have jigs for assmbling the clutch packs etc. If you've confidently build a 400, a 700 will be familiar. There are more pieces to contend with. The pump is a critical area for taking measurements and inspecting for wear. Watch your washers and such so as not to interchange similar, but different parts. Needle thrust bearings usually have a right-side-up.

-dnult

Ok.. Maybe y’all can answer me this one.. Since I don’t think I can find an overhaul kit this holiday weekend, I’ve got my old 1988 suburban with a blown rearend out back. It has a mechanical speedometer. If I change the tail housings and speedo gear or whatever the 92 uses, will it work?

Originally posted by Geezer:
I’ve got my old 1988 suburban with a blown rearend out back. It has a mechanical speedometer. If I change the tail housings and speedo gear or whatever the 92 uses, will it work? ============ yes.

If you remove the tail hosuings off each tranny you will see what needs to be done.


My site:

http://www.geocities.com/crosley_az/700spd.htm

Shows the opposite of what you need, but mayb it wil show you some parts that may help you understand before you start unbolting stuff.

Thanks guys! That helps, I’ll just swap the tranny so I can take my time rebuilding it. I had planned on using a th400 in the Camaro, but if I have a rebuilt 700r laying around I think I can find a home for it…I was also going to use an early model carbureted 350 but now there ain’t much holding the EFI 350 in the old sub…. Somehow one project always gets twisted into another around here… Naturally I have too many Camaro parts in the garage to fit the sub in and as soon as pulled one tranny it starts to rain… Oh well have a good weekend guys, I think it’s time for a 6 pack! :D

Be sure to check the cooler for leaks. And rinse the cooler lines with solvent and blow with air before putting your spare in. Otherwise it will likely suffer the same fate. Either from coolant or from debri from the failed tranny.

-dnult

There wasn’t any thing milky looking, but I’m glad you mentioned cleaning out the lines but y’all didn’t have to leave it to my imagination as to how to get that sprocket for the electronic speedo back on… If I wouldn’t have had a torch to heat it up with, I’d still be beating on it… Oh and is that magnetic pickup suppose to be covered with ½ inch of metallic crud? Thanks again for the help!

VERY LATE POST - but for the archives & those searching for solutions:

The problem is a sticking TV Valve - typically caused by debris/dirt. Unbelievably simple fix.

Start car, have someone put into reverse and hold brake.

Whiole running, remove TV connector from Carb and pull TV cable in-out about 2 dozen times in fairly rapidly succession. Reconnect cable, go for test drive.

That will typically free it up. May have to repeat.

I got this tip from BowTie Overdrives and worked perfectly on my car having the exact same issue. Took 30 seconds to fix.