Hard downshift to 1st when stopping

[BellaBo]

While exercising my m/h today after sitting for about 2 months, I noticed when coming to a stop the transmission shifting to first was very hard and sort of a clunk. This is a Allision 1000. Only 16,000 miles on it. Has anyone experienced this before?

During this same drive, my left front brake started dragging too. The right one has already failed and melted the sensor. Scheduled to take it in for them next Tuesday.

What can I say, it's Friday the 13th.

[DriVer]

Quote:

Originally Posted by Streamerman While exercising my m/h today after sitting for about 2 months, I noticed when coming to a stop the transmission shifting to first was very hard and sort of a clunk. This is a Allison 1000. Only 16,000 miles on it. Has anyone experienced this before?

Steamerman, Do you remember the Grade Brake article I wrote, in that article I wrote that I got a BIG 1st gear downshift clunk when I first got on the road after I had installed a new TCM. Now afterward as the ECM began learning again, the 1st gear down shift clunk didn't happen anymore.

I'm hoping that your 1st gear clunk was an isolated incident and it didn't repeat. Perhaps some type of battery or low power condition occurred to your vehicle. Most times you have to disconnect the battery for this sort of stuff to happen.

Good luck with your Tuesday brake appointment. I hope it gets taken care of.

[BellaBo]

Thanks DriVer,
I only drove the m/h about 10 miles and it seemed to clunk several times. I'm going to mention it to the servicer Tuesday too.

I haven't disconnected the batteries except with the regular disconnect switches. The service provider is about 30 miles from me so maybe it will clear up by then.

As for the brake, the only reason i knew it was hanging up was when I got back to storage I raised it on the jacks to test the original right bad brake. I couldn't turn the left wheel until I got under and tapped on the caliper
and it seemed to loosen up. It didn't get hot enough to damage anything like the right brake did, so, hopefully they will believe me and replace the L/H caliper too.

[jDavid]

The transmission may have some fault codes that need to be reset. Also if you look in your owners manual for the Allison, there are some simple test you can perform. I had a problem with mine once and ended up taking to a truck service center who did a complete check and reset. Shifts like new.

[BellaBo]

Thanks for the tip JD, I'll have the servicer check it out Tuesday. I'm not showing any check engine or warning lights except my ABS light on due to the brake failure, but it's worth checking with them.

[Full-Timers]

When I first took possession of my motorhome back in 2004 with 600 miles on the odometer it was doing the same thing. It continued for a while so I called Allison. They basically told me that happens and there is no problem with it. It went a way after a while so I figured it just had to learn my driving style. Recently I had a crankshaft position sensor fail that made the motorhome stumble a bit while driving and my Trans light came on. Now it seems to be happening again. I am sure it will go away again after a while.

[BellaBo]

UPdate......... I just got 3 calipers and three ABS sensors replaced and now the hard downshift is gone. The servicer said it is probably caused by the ABS sensors that were melted.

[DriVer]

Quote:

Originally Posted by Streamerman The servicer said it is probably caused by the ABS sensors that were melted.

Yes, I would agree!

[RetiredBob]

Quote:

Originally Posted by DriVer Do you remember the Grade Brake article I wrote,

As a new owner, I'm reading back through a number of older threads. Where can I find this GB article?

[edgray]

RetiredBob: I think this is the article you seek: Ultrapower Grade Brake Project

Please be aware your new chassis came with the Allison TGB already installed, and the aftermarket product is not for you. ED

[RetiredBob]

Thanks, wasn't aware the article was on the UPGB.