Transmission bit it!

Ouch.

After pulling out of my work parking lot tonight coming home, I accelerated to get into traffic. It seemed to hold into first gear a little longer than it should have, then it shifted into second. Violently. It then downshifted back into first. Well, now it won't upshift until I let off the gas and this is what I discovered. Whatever caused that hard shift broke something internal in the transmission and now 2nd gear is history. It works in first, 3rd and OD but not second. I sense another transmission replacement in my future.

Perhaps someone here has experienced that sort of failure with their TH700R4. If so, what broke (without yet breaking the tranny down to look at it)?

It doesn't have OD, thought it did.

Edit - Reaction sun shell - yup that'd do it.

My 4L60 did something almost the same as that, but it turned out it was an electircal problem.
You might want to check on that...

My 4L60 did something almost the same as that, but it turned out it was an electircal problem.
You might want to check on that...

The only electric on mine is the TCC - it's not the E version.

Want a wild guess? Splined hub on the reaction sun shell. If that's what you find, DON'T use a factory replacement shell, but try to find a TCI "Beast" sun shell. The hub is reinforced. Other possibilities are the valve body, 2nd accumulator leaking, 2/4 band or servo problem, or low line pressure.

I haven't dug into it yet (too tired to tonight), but after pulling the pan and filter and acknowledging the entire lack of debris of any kind - including clutch wear particles - I am now almost 100% positive that it's the reaction sun shell. I've now got the transmission out and tomorrow I will break it down and inspect it.

Just for shits and giggles, I pulled the 1-2 accumulator cover off and inspected the spring within as this was the cause of a slipping 1-2 on the other one (the spring was broken into 3 pieces), and discovered that this spring was broken into 2 pieces although the broken section was only about 1/2" long and not affecting height.

If i were to take a guess (as I have had alot of tranny problems with the 700r4 in my 88, I'm on #3) I would guess the sun shell.

MOnty, I pick door number 2! Well, well, well, what's behind door #2? Let's take a look. Why, it's a broken reaction sun shell!

And it is now fixed. With another transmission.

Oh, that's sad. You went all that way, and didn't fix the trans? The new (good) sun shell is about $45. The new wear surface/seal kit is about $100. Accumulator spring, $Dirt. You could have had a very fresh, stout trans for next to nothing. Then again, if you still have the core, you still can have that fresh trans at your leisure.

Glad you got it running. Better hope the replacement has already been upgraded.

Oh, that's sad. You went all that way, and didn't fix the trans? The new (good) sun shell is about $45. The new wear surface/seal kit is about $100. Accumulator spring, $Dirt. You could have had a very fresh, stout trans for next to nothing. Then again, if you still have the core, you still can have that fresh trans at your leisure.

Glad you got it running. Better hope the replacement has already been upgraded.

Don't worry - that transmission is getting rebuilt with a Beast - it will eventually go back in, but the one I put in last night was already rebuilt (albeit with a stock sun shell) and is being used as an interim.

That was the plan all along - the trans that's in it now has been sitting in my storage locker for the past 6 months waiting patiently for this day to come. :)

Oh and as for the 1-2 accumulator spring, it was $Free. It's nice to know the guy at the local Cottman. :) A little background on the unit that's now in it is that it was in it up to last September. It had a severely slipping 1-2 shift so I replaced it with a unit I got from Ecology Auto Parts for $50 - that would be the one with the now-broken sun shell - and the problem with the one I pulled out was simply a broken 1-2 accumulator spring. It was in 3 pieces. When I broke the unit down, I was thinking clutches would be burned but that was not the case. Still, I replaced all of the clutches, band and seals to freshen it up. The only problem with it is the fact it's a 1984 w/27-spline input shaft.

how do you guys learn this stuff on these trannies

thats crazy

good luck

Might not be a 10-vane pump in that older trans, and it likely doesn't have the aux valve body. Still, as a replacement, a working trans is better than none.

Might not be a 10-vane pump in that older trans, and it likely doesn't have the aux valve body. Still, as a replacement, a working trans is better than none.

It does have the 10-vane pump, but it does not have the aux valve body. There is no question the other one is a better one overall, but this one works and allows me to drive the car while I rebuild the other one.

like to use the beast now ,you get a chance to try one. like i said befor thay work very well

like to use the beast now ,you get a chance to try one. like i said befor thay work very well

I've got one, recommend it to anyone who tears one of these transmissions apart. They're not much more than an OEM part, but could save you money and hassle in the long run.

i install the beast in every rebuild i do,and there are a lot of them. but like you said thay never brake again .thanks