Suburban Transmission

[mlogrady]

This is a long one...

 

I have an 89 Suburban with the 5.7. Has around 152K, but I have only had it since 128K.

 

Transmission is disengaging in drive and overdrive. Works fine in 1st and 2nd, when it shift up to 3rd feels like it totally disengages. Can manually shift to 1st or 2nd and works fine also.

 

Was on the low end of fluid, but not that bad. Has been running 0 - 25 F for the last month here. My teenage daughter drives it most of the time, just to and from school, which is only 3 miles away. Doesn’t get very hot, plus don’t know if she has a lead foot when I am not around...

 

I towed a 5000 lb travel trailer with it this summer about 3500 miles without any trouble. Haven’t towed again since then. Always towed in D, not OD. Put on a large cooler and had the fluid flushed before the trip.

 

I have rebuilt a few engines, but never an auto tranny. Any simple check I can do that would keep me from having to rebuild/replace it? Here is what I have according to 2 different sources for the RPOs.

 

MD8

TRANSMISSION, AUTO 4 SPD, THM 700 R4

TRANSMISSION,4-SPD AUTO (THM700R4)

 

MX0

MERCHANDISED, TRANS, AUTO PROVISIONS, O/D

MERCHANDISING OPTION ONLY-DO NOT CATALOG

 

V02

RADIATOR, HEAVY DUTY, WITH TRANS OIL COOLER

RADIATOR,H.D. W/H.D. TRANS OIL COOLER

 

 

If I do have to replace it, is there another transmission that would be a better option for towing?

 

Thanks...

[tfpary]

Doesn't sound good, I would guess that the 3/4 clutch is burnt up. It actually isn't all that hard to take it apart and replace the clutch disks, the problem is that at high mileage you are apt to find lots of wear on lots of parts. The pump for example. If this vehicle is only used to by your daughter (beats the heck out of a Civic or Accord or Neon as far as I am concerned) to go to school, a used tranny maybe the answer. I bought a 700r4 for $50, and it turned out to have just been rebuilt. There are millions of these trannys around. Or if you have the cash, maybe a rebuilt from a shop and install it yourself.

tad