LRE Drums Powdering Splines

[smsazzy]

Has anyone else out there had any issues with the splines on an LRE drum powdering? I had a nearly brand new LRE drum that had runoffs only time on it start to lose the splines after 1 session this past weekend. They literally started turning back to powder form. They were tightened to 325 ft/lbs prior to the weekend, and otherwise were properly maintained.

I have heard from a few others that they have seen similar issues and was wondering if this is a wide spread issue, or if maybe we just went through a bad batch.

[Matt]

I have had one case where the drum would wooble on the spline even though it had just been tighten. I replaced the drum and it began to wooble after two runs on the track.

I checked the spline and it was the problem. I replaced the axle and now have many many runs on the drum.

Short story; check the axle. It might be the problem.

Matt
FV61

[FV90]

Looks like I have the same problem. I will be replacing my axles.

[smsazzy]

The axle is fine. The splines on the drum are visibly powdering. I replaced the drum with another, but YOWEE! They are expensive.

[Dietmar]

Stephen:

have to ask...why 325# ????

Dietmar

[SR Racing]

We have the older harder, shims for those that need them. However, we have never had a problem with the newer ones, but... We always torque them to 300# and then after the first session or two on them we loosen and re-torque them to 300+ again. (and it doesn't hurt to check them again after another weekend.)

We haven't spun a drum (or axle) in 20 years. This includes FST.

In regards to an axle leaking, yes the root cause is probably a seal on install problem. However overfilling a transaxle WILL break the camels back. We see far higher temps, with 1.5G plus turns, and many people are using a lighter weight gear oil. The VW axle seal set is hardly a precision component and will seep when beat up on the track. A level 1 inch below the fill hole is always recommended. The original VW needed a higher level since it never saw anywhere near 1/2 of the G forces, and the rear axle bearings get their lubrication from the tube slosh.
There is a drain hole in the bearing retainer for any gear oil that gets past the seal. It is routed to hopefully keep this oil from the brake shoes and drum. But you will see it on the backing plate and tires if the leak is substantial.

[smsazzy]

Stephen:

have to ask...why 325# ????

Dietmar

That was recommended to me when I started racing 5 years ago. I use the Torque Meister and then set my tq wrench to 33 lbs I think it is.

[brian]

Sometimes new LRE axles won't go on all the way and I have to abandon the flanged nut for a session or two then put a flanged nut and retorque. I've seen several have problems with axles that weren't a problem with other drums. There's little doubt that these drums are made of harder and more brittle material. While they don't crack, they will shatter in an accident. I've had several loose the threads and have to be heli coiled.