Filter cover bolts sheared off due to factory defective design?

[yachtnman]

I have an 04 4000MH that was taken in for a transmission service.

The service shop says that when they tried to remove the bolts to the filter covers, the bolts sheared off and now I must come up with an extra $750 to purchase a repair kit and pay the labor to repair it.

My shop tells me they have had about 20 of these same issues on prior services and it is because Allison did not use steel inserts vs. aluminum. They tell me they now have changed that design to steel....why is this not a factory recall?

So what they are really telling me is that Allison made a transmission that cannot be serviced without replacing major parts?

It would be like Chevy telling us that every time you have an oil change you must replace the oil pan?

Can anyone help me here to understand what I am being told and/or am I being led down the merry suckers path?

I have contacted Allison who gave me a number of a field rep...who has not returned the call.

Thank you in advance for your help.

[1ciderdog]

What model transmission? I've removed the filter covers three times on my
Allison without problem. Perhaps during a previous service the bolts were not correctly torqued?
Safe Travels
Bob

[powerboatr]

not to defend allison, but they have many of these of puppies on the road in all kinds of equipment.
sounds like the last service place over torqued the bolts
or the recent place "tightened" them instead of loosening them (yes it happens more often than you think)

i haven't seen an aluminum anything since the early 80's that didn't have a helicoil type insert to save the threads in the softer alum


i would certainly ask a few tough questions of the shop...and also call allison to inquire

[Mr_D]

No Helicoil inserts in the Allison covers. They don't need a bunch of torque to seal correctly. They do make a kit to repair them if needed.
I've also done mine three times with no problem.
Someone overtorqued the bolts and stripped the threads, and even then it should only happen to one, the rest should be OK. The only way ALL the threads could be stripped out is if, as someone already said, the worker tried tightening them with an air wrench and stripped them. As I remember they only take inch pounds and not foot pounds (going from memory here and I just might be wrong).
You don't need the factory kit, the correct helicoil kit would do althouth the stripped out thread is buried pretty deep in the case.

[Oldkarphart]

I agree with the prev. post that overtighting was most likely the cause.....Heli-coil is the best way to "fix it" now.
Another point to be made, that it's a good idea to use anti-seize on the bolts when going into aluminum.....

[Gary RVRoamer]

I think your shop is just trying to shift the blame and make you pay for their screw-up.

Are the bolts on the 4000MH any different than the 3000MH? I thought that was aluminum too.

By the way, the reason it would not be a recall is that there is no highway safety issue involved. NHTSA does not do "recalls" to save your wallet. Allison might elect to do a "service campaign" if it thought there was a widespread quality problem, but I don't think that's the case here.

As has been said, there are thousands of these transmissions in continuous heavy duty use and I have not heard of any widespread problem with filter cover bolts being stripped during changes. Had my filters replaced by Freightliner in Gafney just a few months ago.

Suggest you offer to pay for the repair kit and tell them the labor is theirs. That seems generous under the circumstances.

[Mr_D]

Quote:

Originally Posted by Oldkarphart I agree with the prev. post that overtighting was most likely the cause.....Heli-coil is the best way to "fix it" now. Another point to be made, that it's a good idea to use anti-seize on the bolts when going into aluminum.....

Remember though, if you lube the threads you MUST REDUCE the torque on the bolts unless the manufacturer states the bolts are to be lubed!
My lug nuts are a case in point, they say 500 ft lbs and factory info says lubed.
Normal torque values are for dry threads, if lubed they slip easier and the bolt tension goes too high.
It varies with the lube but -20% is a good starting point.

OP: Another point is the the bolts will NOT "shear off". They are steel and the case is aluminum, they can strip the threads either from over torquing or corrosion. Corrosion is not a problem in their location as they are not exposed to the elements.

[Iron Man]

I agree how does a steel bolt "shear off" when screwed into an aluminum case. Maybe the case threads are stripped but the bolts could not have been broken. You need to physically see what the issue is.

[Dunner]

Even if the steel bolt was seized in the aluminum, it would pull the threads out of the aluminum before snapping a bolt. My aluminum block LS1 Corvette motor doesn't have any helicoils. Neither did any of my aluminum motorcycle engines.

[Bob Reed]

Get it out of the shop NOW !--your dealing w/a shop of fools ! as stated ,there is no way to break the steel filter fasteners in the trans. pan,even if they were tightened w/an air tool. I would suggest that if the threads are stripped that you have a correct size 'timesert' installed as opposed to a heli coil-they are solid inserts and are less likely to leak.