190 body resonance

[jack-n-gill]

Hi Guys
My 1989 190 2 litre has a strange body resonance. It only occurs in 5th.gear when power is applied at 60MPH up to about 70. equates to 2000 RPM up to 2300ish.
It doesn't do it in any of the other gears from a similar rev range.
Much more noticeable in the back. Makes a booming sound like driving over a newly laid concrete road surface- sort of!!
Any ideas what could be the problem?

 

[andy_k]

I'd suggest rather than it being linked to the revs it's linked to the speed.

Check, rear wheel balance, wheel bearings, diff and tyres (is it possible one is slightly out of shape?) all of which could create noise from the rear.

Andy

 

[jack-n-gill]

Hi Andy
I suppose it could be but it don't happen at the same speed in any other gear.

I was wondering if it could be a bearing, but out of gear and coasting there's no sign of it. :?

Stumped me!!

 

[flagstaff]

i had this (or a similar-sounding) problem with a 190D one time. turned out that the prop shaft centre support bearing bush was badly worn. can't hurt to chck. if it's orn it's very obvious - there'll be a gap between bush and prop shaft, flaked rubber etc ... hope this helps

 

[jack-n-gill]

Cheers Flagstaff
I'll crawl under it at the weekend and have a wiggle. :?