Trans seems to work fine except when you downshift to second gear it doesn't hold truck back...it's like it's in neutral...when you accelerate in second it doesn't slip...but when you back off throttle it free wheels and seems to be disengaged from engine. Any help would be much appreciated.

 

Maybe intermediate one way clutch, but it holds in 2nd acceleration and over runs in decel, so guessing....

 

No, it isn't the one way clutch. It's the coast clutch. The trans needs to come out and get torn down to fix this.

 

I was thinking coast clutch,but the only in second gear thing threw me.

 

Thanks for replies everyone! This transmission was replaced 20 000Kms ago. I think the throttle position sensor was bad the whole time...causing torque converter to unlock intermittently... I just changed that recently and that solved that problem. I'm a bit confused because it holds back and decelerates in drive and first gear just not in 2nd. Could it be anything else? Also shifts smoothly and firmly on up shifts. So if I leave it...do you think this problem will leave me on side of road? Probably no warranty as I wasn't the owner when trans was replaced. Thanks in advance for anymore input anyone has.

 

That's new information. You didn't say earlier it will hold back in first gear. In this case, I suspect it is the intermediate band. This band is only applied when the shift handle is in the 2 position. Is this when you don't have engine braking?

 

Hi Mark, sorry I didn't explain that more clearly at first. Yes correct, no engine braking only when shift lever in 2nd position. Can you tell me how to fix this?

 

Sure! Take the trans out, tear it down, find out what broke, and fix it. It is something mechanical, nothing electrical can cause this.

 

Ok thanks for the bad news. It doesn't bother me that much and I'd never have known if I didn't try downshifting on a hill. In your opinion will this affect reliability if I leave it?

 

No, it probably will not affect reliability. If you don't move the shifter to 2 the intermediate band is just along for the ride. It doesn't do anything until the shifter is moved to 2.

 

Thanks Mark for your help with this! I've seen your responses to other posts too, and it's obvious you know these transmissions. Thanks again for taking the time to help out! Thanks to all others too that helped out, any and all input is much appreciated!

 

One more question here...I took truck by transmission shop...guy there says in 2nd gear position coast clutch should be energized...he thinks my coast clutch might not be energized manually in the 2nd position. Would this make sense?

 

Ok...now getting confused. I took to 2 trans shops. Other guy left me a message saying in second gear position it shifts coast clutch hydraulically but not with a solenoid. He says he has seen this problem with a leaking solenoid pack...says won't know without dropping pan and solenoid pack.
Any thoughts on this diagnosis?
Now not sure which shop to use?

 

I think they are both saying the same thing, just in a different way. I think they both know what they are talking about.

When the shift handle is in the 2 position the coast clutch is not energized by the solenoid, but by a hydraulic circuit.

 

Ok thanks Mark. So maybe it is the coast clutch and not the intermediate band? If this is the case and it's just a leak at solenoid pack...maybe trans won't have to be pulled?