PDA

View Full Version : Allison bind up

chromedome1
09-14-2013, 05:04 PM
Need help. Had a local Trans shop instal GMAX 6 kit in 2008 Lmm. Installed in truck and set to relearn, had reverse but no forward. When in forward truck didn't move and acted just like a Trans brake. Pulled and builder checked, found c1 back fill valve cap broke from air checking above 90 psi. Reassembled with new cap and new pump. Reinstalled today, same issue reverse fine but bind in drive. Checked all connections and cleaned all appear to be ok. Need truck going help. Thanks

Verified that c3 and c4 pistons are correct per Ernie@Suncoast
Diesel Tech
09-14-2013, 07:05 PM
Many things could cause it but they are all internal. Did they check all the clutch pak clearances? Could be a stuck valve in the valve body too so you may want to drop the valvebody and take it apart and clean it. Most likely that's not it but its a bunch easier than pulling the whole unit again without giving it a shot.
chromedome1
09-14-2013, 08:49 PM
Could tcm command such?
Diesel Tech
09-15-2013, 03:26 PM
Anything is possible but not very likely the TCM.
DPC
09-15-2013, 09:45 PM
Call Suncoast, they will point you in the right direction.
STROKETHISF350
09-15-2013, 11:45 PM
I'd give mike L a call he's without a doubt the best with allison and loves troubleshooting problems
chromedome1
09-18-2013, 08:53 PM
Fixed guys, thanks for help. Bad valve body
STROKETHISF350
09-19-2013, 04:53 PM
Bad valve body? What exactly was wrong with it, I'm assuming you're builder didn't know what he was doing while installing the trans go
chromedome1
09-20-2013, 08:27 PM
Not sure I can blame builder let's just say it was fine before the install but they made it right thankfully and great so far. Thanks
STROKETHISF350
09-20-2013, 08:54 PM
Idk bud I wish you the best with your trans, Allison's are fairly easy to build and will last if the builder knows what there doing. From my own experience with suncoast I hope for you're sake that the builder was competent enough to get the clearances right, the suncoast kits are top of the line but it's only going to last with the proper clearances. When I put mine together 3 0f 5 clutch packs weren't right and if I hadn't checked I would have screwed myself.