Strange transmission behaviour...

[linx310]

This has happened to me twice now with my M1009 and it has me a little concerned.

When I shift into reverse I don't feel the transmission engage and when I give it some throttle the engine revs and nothing happens.

I found by shifting the column all the way to the end and then back into park one or two times it will then engage and I can back up.

When driving I notice no slipping out of gear or really hard gear changes. I have only driven it a few times and had it only up 60 mph once though.

Does this sound like the vacuum modulator is going out?

 

[DokWatson]

I would first look at the shift linkage on the left side of the transmission, sounds to me like its a little out of whack.

 

[1986Blazerk5]

I would first look at the shift linkage on the left side of the transmission, sounds to me like its a little out of whack.

X2 on that if it was the modulator it would be when shifting fron 1-2 or 2-3 although transmissions are not my specialty

 

[mr.travo]

I bet you it's the shift linkage. My M1008 at work has the exact same problem. I just need to set aside some time to fix it! LOL!

 

[CPAPPY]

I found that all my 3 M1028 shifted and responded much better after filter and transmission oil change. My last truck i changed the filter and fluid acted the same as yours .

 

[caladin]

I would first look at the shift linkage on the left side of the transmission, sounds to me like its a little out of whack.

Now if I could only figure out how to "fix" the shift linkage

 

[Dave Kay]

If I were you I would FIRST get busy with the TM's on how to check/adjust the shift linkage. It's really simple. But left undone, this minor problem could burn-up trans clutches in short time... it's an age-old GM tranny problem easily fixed.

 

[rlwm211]

Reverse is actuated by a spool valve and if you have to fiddle around to get the gear to work, you have a situation where the linkage needs adjustment as it has been mentioned.

I do not recall the specific procedure but I have done it before, and it is easy and all you need to do is download the TMs for your truck. If you do not have them already......

They are available at www.jatonkam35s.com

Once you are sure you have the transmission shift linkage adjusted properly, you can see if it is a linkage issue or internal to the transmission.

Hope this is helpful....

RL

 

[rnd-motorsports]

Sounds like a shift linkage issue. For a quick check look at the link that connects to the transmission and then to the frame see if the little plastic bushing is gone. There should be a spring that pushes a tapered bushing into the frame pivot mount. If that is gone get a new one may be all it is! Cross your finger and take a look! Them plastic bell crank bushing break fall out. Easy fix

 

[hogtruck]

Adjustment procedure in -34, para 5-2d. Pretty staight forward.
Regards,

 

[linx310]

Just to let every one know i fixed the problem months ago. I replaced the transmission fluid and have not had an issue since.