Transmission Trouble

[laneriverrunnerm1008]

I was driving my son to school this morning, when something fell out the back of my m1008 truck. I stopped and put the truck in reverse and I heard a clunk sound and my truck would not move in reverse. It shifts through all the forward gears fine just not doing anything in reverse. ( When I bought the truck about three years ago the trans was assumed to be shot, I got it home, changed the modulator valve, fluid, and put a new screen in. From then until this morning I hadnt had any trouble). My question is did the reverse band break if so how much would a fix be or do I need to hunt another transmission. By the way before I changed the fluid, screen, and modulator valve my truck wouldnt do anything in reverse and would not shift out of 2nd. Any advice or suggestions please.

 

[dstang97]

Hmm my truck barley has reverse with out reving The piss out of it and has no second. I think its time for you to have a rebuild

 

[laneriverrunnerm1008]

yeah I have already called a couple of trans shop and they are telling me that the its going to cost between 600 to 900 dollars for a rebuild. I still have 1st 2nd and drive just no reverse. I am wondering if I should go back with with a 700r4. It would be nice to run 55 mph and still hear the radio in the truck. I plan on putting a 4 inch lift with 35" tires, but now I have to fix the transmission. I was hoping the taller tires would allow me to go at least 60 without over doing the 6.2. Ill probably rebuild the original th400.

 

[bigflew]

probably a reverse input shell striped or broken. requires almost complete dissasembly might just as well install new clutches and seals as well its all prety simple.

 

[mrcucv]

id say what bigflew has said is correct i just finished up transmission class and the reluctor sun shell is used in reverse and only that so if everything else is fine that is probably broken.

 

[4bogginchevys]

you could just park where you always have a front exit while you build another transmission. By the time a forward gear goes out you could have a bullet proof 700r, th400, or even a 4l80e. When the trans started slipping last year in my other truck I went and got another. Didn't want to take out a basically working trans yet so I babied it and got another year out of it, the tranny I have now will go 1 year longer than it otherwise would have. Good luck.

 

[319]

Would a 700R4 be a direct replacement in the M1008, or would the converter, drive shaft, and other components need replacing? What about in the M1009?

 

[4bogginchevys]

I think the 700r is about 1/2 to 3/4 of an inch longer, but cant remember for sure. I think it is a definate possibilty but requires a little more investigation. just need to find a 700/208 already installed and get a couple measurements for installed length at front/rear output from engine, and also placement of crossmember with the different adapter.

 

[Bob H]

The 700R4 in stock form is Light Duty at best.
It has a lower 1st gear than the TH400 and of course the overdrive.
the 700R4's are prone to heat failures, and cost 3 times what a 400 does to rebuild.
I am not sure but I believe that the 700 R4's also use a lockup convertor.
as far as a direct bolt in swap, I think it is. That is based on my experience with a trans guy offering me the less expensive option of replacing my burnt 700R4 with a TH400
(didn't do it as the R4 could be on the road that day and the 400 had to be located and brought in)

EDIT:
The 700R4 can be built to handle anything, it takes $$$$

 

[filo]

I would also research the output shaft spline count, if you're going to use your same transfer case.
the crossmember should work
driveshaft lengths might be a concern too. although 1/2" isn't an issue
Shifter linkage will be a bit different too.

There are some things to adjust/modify, but if you do your research and get one that is built up for 4x4 and/or diesel, you will be happy with the OD from a TH700.

a 4L80 is completely different:
for that swap, you will need:
relocate and/or modify crossmember
new driveshafts
transfer case adapter or different one
a computer to run the 4L80 (expensive)

Just my .02