How to Identify a 700r4

[HotRodPC]

Thanks for the info. It's a 4wd so my speedo cable is on the transfer case. I'm just picking up a few cores right now. I've got this one and a 89 k case.

Perfect. You're in good shape then. 89 K case will be one of the more desirable units.

 

[burbboysgc]

Can you use a 4wd 700r4 on a 2wd truck?

 

[HotRodPC]

If you swap out the 4x4 output shaft to a 2wd output shaft and add the tailshaft housing then yes you can. But not without pulling the whole trans apart to swap the output shafts. The lengths are different.

 

[89Suburban]

Does anybody have a 2wd 700R4 trans laying around out of vehicle? I need to know how far the tailshaft sticks out past the end of the case. I am thinking it's under an inch.

 

[HotRodPC]

Does anybody have a 2wd 700R4 trans laying around out of vehicle? I need to know how far the tailshaft sticks out past the end of the case. I am thinking it's under an inch.

It's under and inch for sure. Are you wanting from the end of the tailshaft housing to the end of the output shaft? Of from the seal to the end of the output shaft? I think I have one on the side of the house I can measure.

 

[MadOgre]

Another sign of the later model, more sought after 700r4 for performance builds would be the rainbow on the passenger side of the case in the casting of the case. It is has this rainbow as pictured below between the blue lines, its one of the better performance choice cases.

Also, on the picture above, you can see the K on the passenger side of the bell housing. The K is the stronger case, most commonly found in 4x4 trucks. The K case has thicker bolt lugs at the bell housing bolt bosses. It also has more threaded holes drilled into the torque convert cover. The torque converter cover for the K case uses a much thicker cast aluminum cover with 6 bolt holes instead of 4 and said to better strengthen that section of the case when the torque converter cover is bolted on.The 2wd or Non K case will use a thin tin cover over the torque converter and 4 smaller bolts.
If you are building a high performance 2WD 700r4 and you feel it needs that added bell housing strength, you can use a 4x4 Case, but you will also have to use the 2WD output shaft, and add the aluminum tailshaft housing from a 2WD case that is a direct bolt on to the K case.

I would think that the torque arms that go from the motor mounts to the torque converter cover could also be used in 4wd retro fits into 2wds. That would definitely help if you are using a 4wd case because of bell housing strength concerns.

 

[89Suburban]

It's under and inch for sure. Are you wanting from the end of the tailshaft housing to the end of the output shaft? Of from the seal to the end of the output shaft? I think I have one on the side of the house I can measure.

Yeah end of the housing surface itself to end of shaft, it may only be a 1/4 or 1/2 an inch tops.

 

[Edgar-C10]

Hello everyone,
I'm new to this forum. I just bought a 1987 4x4 Chevy R10/V10 truck for my sons 18th birthday last week & the Transmition went out today. I'm trying to identity the trany, its marked TXMO56H w/MD8 on the housing. Any help is appreciated.

 

[yevgenievich]

Do you have a picture from the buttom that would show the pan and the tail housing?

 

[RetroC10Sport]

TXM - 1987 4x4 K10 700r4.

 

[Galane]

What was a 8TUM170A originally used in? It has the pressure taps so I assume it's a 1988. M of course means 700R4.

What's the TU? I've been looking for but not finding a list or chart listing what the first to letters mean, or what the characters after the M are for.

I need the specifics because I want to know what rebuild stuff to get for improving it, like putting more discs in the 4th gear clutch if that will benefit.

Edit: I called a GM dealer and all they could tell me is it's from a 1988 Chevy truck.

 

[RetroC10Sport]

TUM

MD8 TH700R4

Chev Tr. 87 ser. 10 & 20, conv. cab, 4x2, 8-350 (5.7L)
Chev Tr. 87-89 ser. 10 thru 30, van, 8-305 (5.0L) & 8-350 (5.7L)
Chev Tr. 88-89 ser. 1500, conv. cab, 4x2, VIN model R, 8-305 (5.0L)
Chev Tr. 88-89 ser. 1500, conv. cab, 4x2, VIN model R, 8-350 (5.7L)
GMC Tr. 87 ser. 1500 & 2500, conv. cab, 4x2, 8-350 (5.7L)
GMC Tr. 87-89 ser. 1500 thru 3500, van, 8-305 (5.0L) & 8-350 (5.7L)
GMC Tr. 88-89 ser. 1500, conv. cab, 4x2, VIN model R, 8-305 (5.0L)

 

[vintovka]

I have an 84 GMC Sierra classic with a 700r4 AND has a column mounted shift indicator. Every source says this does not exist I need a diagram showing the shift indicator parts and how they go together Again this is NOT a dash mounted indicator. What Gives?

 

[krautmeister]

I am sort of slapping myself with my purchase every time I find out something that the seller told me that is wrong....

I thought I had a TH350... hell 3 gears only worked and then I somehow "broke it" and only had 2 gears. Tranny wants to drop out of gear and coast when I hit 40mph+... unless I have it in a lower gear and it locks up.

So I think it's a 700r4, which is bitter sweet because I like the fact it's 4 spd as I don't plan on hot rodding it too much. I prefer the everyday drive ability.

So I bought a Modulator valve and governor gear... aaaand it's not even a TH350!!

I finally crawled under there tonight and wondered for a few minutes why there was no vacuum modulator!!!

Can anyone confirm??

You must be registered for see images attach

 

[74 Shortbed]

700's don't have a modulator valve, shift points are controlled by the TV cable and I see MD on the case, it should look like this.

You must be registered for see images attach