My 2000 VW New Beetle manual transmission recently had a new right front axle & axle boot replaced related to a leaky boot. 1st time for this repair. She has 222,185 miles. She’s had regular maintenance done throughout her many years with me and has run/performed great over the years. However since this new axle, she now has a “roar” at higher rpm’s - about 3600 to 3700- under load (shifting between gears, and steadily in 5th).
There’s also a palpable vibration one can feel on your feet if sitting in the passenger front seat.
This roaring and vibration was very significant when I’d first gotten her back from my mechanic, but has seems to have somewhat dissipated over time (axle work was done Aug 17, 2023), but definitely still is there.
Coincidental that this problem has appears literally immediately after the axle was replaced?
Talk is “Maybe it’s the transmission? Maybe it’s the engine?”
What do you think is going on and is the solution to make her as she was?
Welcome to the forum.
You may have a defective axle. Was is new or was it rebuilt?
The wheel bearing may have been damaged by over-exuberant use of the impact wrench tightening the new axle shaft nut on the outer end.
Or maybe not tightened enough?
My mechanic put in a new one. (How could that be verified?)
He says he’s checked everything and it’s all per specs…
The invoice should indicate it. But even brand new units, especially cheap knock-offs can be bad right out of the box. Or it could be a damaged wheel bearing, like @Mustangman said.
Possible the inner joint is not seated all the way and or the 6 bolts are not torqued to spec… If it is cocked a little it could be binding a little… I guess of your mechanic is not familiar with the way your VW axle comes out he/she may have tried to pry it out instead of unbolting it causing damage to the trans…
Is you mechanic a DIY from home or a Pro with years of experience in a shop doing this type of work??
My money is on a defective axle or damaged hub bearing as mentioned above though…
But the noise occurs related to the rpm’s not the axle speed… occurs only under load…
When it’s hanging up in the air (not under load), on a lift, the noise doesn’t occur.
I’m also going to say the mechanic used an impact gun to install the axle nut, damaging the wheel bearing.
Tester
So it doesn’t matter if in gear or not then?? Only related to the engine speed (RPMs)??
Does it make noise just revving the engine??
Does it matter how fast you are driving??
Just trying to understand what you mean by occurs related to the rpm’s not the axle speed
You mean under suspension load or under driving load? You would need to load the suspension (jack stands close to lower ball joints) to see if noise goes away or still there…
Suggest to review the following thread, then ask your shop tech if that could be the problem.
It was definitely a new axle.
The mechanic is very seasoned - been in business for 35+ years
I had rather you of answered my post #11 (3 above this one)…
Doesn’t make noise just revving.
Does make noise if I push her (higher RPMs) a little more than I normally would before shifting to the next gear (1 to 2, 2 to 3, 3 to 4, 4 to 5), then the noise stops as she settles into the next gear. Once in 5th, increasing the speed/RPMs the noise is constant (at about 70 to 75mph /37-3800 rpms).
And shifting back down, same situation in reverse: noise on initial downshift which decreases as styling into the lower gear (slowing down /lower RPMs)