M1008 transmission possesed

[Jersey4x4]

OK I bought this truck direct from the gov. didi some minor repairs over a few monthe then finaly tagged it. I drove it and it was shifting so hard 1/2 and 2/3 that the back tires would chirp(NOT COOL IN SNOW) so I replaced all the vac. lines. Still shifting hard so I replaced the modulator with a TM50 from standard which is a direct cross from the PM number and it looked totaly different from the old one and now it shifted way too soon but still hard so I adjusted the modulator to get the shift points correct and it was at the right shift point but still hard. I replaced the vac. pump now the funny part, it shifts like a wet sloppy sponge at when heavy on the peddle almost like it is gliding into gear. so bad you dont even feel the shift, but it shifts ok at slow granny driving. I replaced the TPS on the IP and no change. Next day fired it up let it idle down and warm up went to drive and it hit 35 in first then went to second and almost instantly went into third but the 1/2 shift was a wheelie making shift. so I droped my son off at school and while I was driving I noticed the shift points dropping and loosening up to the wet sponge shift again. I even added a vac. canister for reserve vac. and it did not help. I can not find the vac. modulator or TPS adjustment procedure in the TM so that might help but this thing is driving me crazy. Oh yea if I manualy shift through the gears it is absolutly perfect.
And it wont down shift to first unless you get almost to a complete stop like baby crawling speed but if I manualy put it in 1 it is fine. Any help would be great and a copy of the TM on the adjustment procedure would be a real help or even a manual number and page number. Thanks alot

 

[Westech]

same thing with my m1008 right now i swapped out the vac mod on the side of that trans and it got a little better but sometimes it on 3ed by 10 mph.

 

[CUCVFAN]

Rotate the Vacuum valve on the side of the IP ( what you are calling TPS? ) as far counter clockwise as it will go. This will lower the shift point as low as it will accept. Then, adjust it from there.

 

[Jersey4x4]

Re: RE: M1008 transmission possesed

Rotate the Vacuum valve on the side of the IP ( what you are calling TPS? ) as far counter clockwise as it will go. This will lower the shift point as low as it will accept. Then, adjust it from there.

I did that but why is it changing on a daily basis. I cant think of what the deal is other then valve body problem. Some times it is fine and others it just sucks. and like the other post say sometimes it is in 3rd by 10 or 15 MPH

 

[CUCVFAN]

RE: Re: RE: M1008 transmission possesed

You can download the TM from this site (-20, page 3-64). On the left side at the bottom, follow the Technical Manuals link. The gauge block is somewhere around .6" thick (I have the number somewhere around here), but whatever finger turned sideways is about that thick is what I use to get close. If you've got really big fingers, then use your finger flat, I guess.

Also, make sure the vacuum lines on the valve are not reversed, although they should be attached to a connector that fits one way. Try totally unplugging the vacuum line at the modulator and see if the transmission becomes more consistent. In that condition (no vacuum), it should shift by the regulator only, so you should get very firm shifts at more predictable speeds. If not, look into the regulator or internal tranny problem. If it shifts consistently, then it's got to be modulator or vacuum valve/line related.

 

[bus63kombi]

RE: Re: RE: M1008 transmission possesed

My M1009 shifts very hard and way to late. It is a real pain. So I am converting it to a SM465. I will like that so much more.

 

[mangus580]

RE: Re: RE: M1008 transmission possesed

Sounds like a vacuum problem bus....

 

[bus63kombi]

RE: Re: RE: M1008 transmission possesed

I replaced all the vacuum lines. But it is an excuse for me to convert it to a stick shift. While I have the engine out I will do my heads and IP. I really should pull the left had to make sure all is well, and make sure it is still true.

 

[mangus580]

RE: Re: RE: M1008 transmission possesed



Its also possible that the vac pump is shot, or the variable 'switch' on the IP.


On the original topic.... I wonder if the governer on the side of hte tranny is sticking? I would suggest a fluid/filter change ...

(The TH400 does have a governer right? I just remembered, i have the 700R4 now )

 

[bus63kombi]

RE: Re: RE: M1008 transmission possesed

I do know that the switch on the IP pump sticks on mine. If you go beat it with a screw driver it shifts nice for a while.

 

[mangus580]

Re: RE: Re: RE: M1008 transmission possesed

I do know that the switch on the IP pump sticks on mine. If you go beat it with a screw driver it shifts nice for a while.

Well that explains alot right there.... buy a new switch, done deal

 

[bus63kombi]

RE: Re: RE: Re: RE: M1008 transmission possesed

True true, that would be easy. But I have my heart set on converting it to a stick shift. So i think that is the path of my madness for right now. For the meanwhile. Is there anywhere specific I should go for the switch?

 

[CUCVFAN]

Re: RE: Re: RE: M1008 transmission possesed

On the original topic.... I wonder if the governer on the side of hte tranny is sticking? I would suggest a fluid/filter change ...

(The TH400 does have a governer right? I just remembered, i have the 700R4 now )

Doh! Governor, Yes. I called it a "regulator" in my last post, but the governor is what I was referring to. Unplug the vacuum and the governor will control the shifts. Maybe it is sticking or maybe it was swapped from something else with different gears/tires/etc...