Screeching tranny

[Dirttracker5]

Having problems with my tranny making a screeching noise everytime I pull out of my pit stall and in reverse. It's a bert and just got it rebuilt but it's always done it. It does it every time and I tried pushing it at just an idle I tried light throttle I tried bunch of throttle and just hold it in quick. No way around it. Any thoughts?

[TLCT1]

I had the same issue, switched back to plain old type F trans fluid and that cured the problem.

[RacerX10]

I had the same issue, switched back to plain old type F trans fluid and that cured the problem.

My old one usually made that screeching racket .. I ran 20w50 in it. About to fill my recently rebuilt Bert .. what were you running in it when it was screeching ?

[TLCT1]

Amzoil synthetic trans fluid.

[Matt49]

Ditto on the Amsoil Synthetic ATF. That screeching that you're hearing is clutch-disc to clutch-disc action with NO lube. A good fluid will help a bunch with that. If you still have issues after that, your problem is deeper...meaning you might need a new clutch pack due to travel issues from excessive wear. Service your Bert transmissions at least once per season and change fluid about every 10 nights of racing is my best advice.

Editing - just realized it was the OP that said they were running Amsoil Synthetic ATF. If that's what you're running (at the proper level) and you're getting screeching, you likely have some other problem with travel in the clutch pack.

[TheJet-09]

I by no means know the inner workings of a Bert, but isn't there an "override" mechanism that breaks free if too much power is applied, and when that happens it screeches? Mine does it sometimes if I'm having to throttle it to make it up a hill or something (Peoria Speedway is a prime example), like exiting the track after a race. I run basic Type-F fluid, but change it every two nights.

[Matt49]

I can only speak for 1st Gen Berts as I rebuild my own. There is no such mechanism for the clutch in them. It-s a slave cylinder that basically works just like brakes. The harder you press the pedal, the harder the counter gear assembly compresses together with the clutch discs between the front and back of the assembly which eventually makes them turn the same speed.

[TheJet-09]

I stand corrected then. It was something I had heard but never researched or found in writing. I experienced the same though with the first Bert I had 20 some years ago, as well as my current one which is about 3 years old (both LMZ). I will say, when it screeches most everyone nearby looks at me like "what the heck was that?"

[petesbuyin]

3 things I have found when I rebuild a Bert that causes screeching: 1) Putting to much shim in the front of the countershaft. This causes the clutch drum to rub on the casting for the reverse idler shaft and not let the clutch completely disengage. The slight drag on the clutches will cause the steel discs to glaze up and screech. 2) Not soaking the clutch discs before assembly. The discs are lubricated by splash and if they are not soaked in ATF for a couple of hours before assembly, the discs will be dry on first use, again causing the steel disc to glaze up and cause a screeching. 3) Not cleaning or replacing the steel discs on rebuild. If the discs are glazed and not replaced or sanded to remove the glaze they will screech even with new clutch discs. The fiber discs are included in a minor rebuild kit but not the steels. The steel discs can look perfect but still have a glaze on them. If I am not replacing the steel discs (which is rarely needed) I always sand both sides of them on every rebuild. This is most likely your problem as you said the trans screeched before and after rebuilding it. As far as fluid, the trans that I rebuild that use cheap basic type F ATF fluid always look better inside than the ones that use synthetic or the so call "miracle fluids".

[RacerX10]

3 things I have found when I rebuild a Bert that causes screeching: 1) Putting to much shim in the front of the countershaft. This causes the clutch drum to rub on the casting for the reverse idler shaft and not let the clutch completely disengage. The slight drag on the clutches will cause the steel discs to glaze up and screech. 2) Not soaking the clutch discs before assembly. The discs are lubricated by splash and if they are not soaked in ATF for a couple of hours before assembly, the discs will be dry on first use, again causing the steel disc to glaze up and cause a screeching. 3) Not cleaning or replacing the steel discs on rebuild. If the discs are glazed and not replaced or sanded to remove the glaze they will screech even with new clutch discs. The fiber discs are included in a minor rebuild kit but not the steels. The steel discs can look perfect but still have a glaze on them. If I am not replacing the steel discs (which is rarely needed) I always sand both sides of them on every rebuild. This is most likely your problem as you said the trans screeched before and after rebuilding it. As far as fluid, the trans that I rebuild that use cheap basic type F ATF fluid always look better inside than the ones that use synthetic or the so call "miracle fluids".

That's a lot of great info for your first post

I know where to go for Bert info now !