Transmission Drain Plug

[Fratto]

Good Morning! Just got a call from Prevost Dallas and during our transmission service, the drain plug came out with its threads. So the drain plug is now stripped and will not likely stay in.

They called S&S and they want to replace the full belly pan. Another shop can make / install a different plug but it is still $1,500 or more!

Anyone have this issue and solved it for less than an arm and a leg?

[Joe Camper]

M.I.F.

Acranym for Maintenence Induced Failures

Sometimes design induced.

Sometimes age of components induced.

Sometimes mechanic induced.

a combination of some or all the above

Wonder how many times its been drained? Wonder the torque spec on that plug is going into aluminum? Wonder how many times it was put in with a torque wrench? Wonder if the book has any special notations. Those filter threads r getting stripped alot too.



Mr. Mechanic if u would please let me know after u have removed filters and draind fluid and BEFORE reassembly if u came across any bad threads on that trans. I want heilcoil on any bad threads please be carful take your time and use torque specs on every nut and bolt thank u.

[Fratto]

Prevost cant fix this. At their recommendation, I talked to Inland Truck and they will do this for $450 to $500. Not sure if that includes reclaiming the brand new fluid or not. According to Inland, this happens more than you think. In fact they just did another one a couple of weeks ago.

Crossing my fingers that Prevost is right and the plug will stay in for the short trip from Prevost to Inland.

Unfortunately they are a week out so this weeks trip will be cancelled. May just leave the bus at Prevost to limit risk of driving with the bad plug.

[wjohnson720]

B500 Oil Pan - $300 used on ebay . . .

https://www.ebay.com/itm/Allison-Alu...-/292043568877

Make sure that is the correct part number.

Get a gasket, reuse the existing bolts, buy a plug. Torque properly and away you go!

[Fratto]

Thanks Bill, that is a great idea. Unfortunately, I do not have a place where I can do this kind of work. If you add labor and fluid to the $300 I think that the stripped plug kit installation will be less money.

[truk4u]

Same thing happened to me years ago at Prevost Nashville. They had a kit that over drilled the pan hole and cut new threads adding a larger plug, problem solved. At the time I had a 97 Royale and they only had one tech that could do the fix.

[Fratto]

Update; Prevost Fort Worth found a longer drain plug that was able to reach some of the clean threads and is confident that this will hold until the next time it is removed for service. So for now, I am going to trust them and keep an eye on that plug.

During our next transmission service I will have the larger plug installed or bring my own pan, which ever is cheaper.

Tom, you are right. I do not know the particulars of this retrofit, but Prevost wont do it and Inland Truck said that they only have 2 technicians that can perform this install.

[Gil_J]

The filter housing plates often have stripped threads because the mechanic didn't torque them correctly. I don't recall the torque rating, but it isn't much. As for the drain plug, aftermarket plugs that use a compression rubber plug work great and are generally available for any size drain plug.

[Fratto]

Gil, that is another good idea. I have used the compression type on old cars when I was growing up. Anyone have experience with them in commercial vehicles?