Thread: GBR Utah rear prop balance issue

Make sure any greasable joints are fully greased. I have a vibration in the stock rear propshaft from a dry bearing.

Its all greased unis are all okay I was just checking if anyone had issues with a new unit being out of balance. It just seems strange there are no weights on it.

Originally Posted by nigelbuilding1984

Its all greased unis are all okay I was just checking if anyone had issues with a new unit being out of balance. It just seems strange there are no weights on it.

When you fitted the new unit did you also fit a new flex coupling as that is usually the source of vibration if you didn't.
Nick

Nick I think the GBR units do away with the rotoflex , this , on its own will cause problems unless it's perfectly balanced IMO

op , have you removed the shaft and gone for a drive to make sure that is the problem ? ( assuming you have cdl )

I would also think it should have weights

Originally Posted by nigelbuilding1984

... I get a bad vibration from 80 to 110 coming from the rear. ....

What engine, what trans, what gearing(ie. at how many revs are you doing at 80 and again at 110)?

Originally Posted by AK83

What engine, what trans, what gearing(ie. at how many revs are you doing at 80 and again at 110)?

V8 auto lt230 1.22 4.11 diff gears 33 inch tyres. The gear it's in doesn't affect the vibration. Revs would be from 2300-2650 rpm roughly.

Originally Posted by nigelbuilding1984

V8 auto lt230 1.22 4.11 diff gears 33 inch tyres. The gear it's in doesn't affect the vibration. Revs would be from 2300-2650 rpm roughly.

I'd be suspicious of the torque converter(now with the recent experience brother had on his Auto TD5).

Exact same issue with vibe from 80-110(ish).

We rebuilt the front prop, then found about 5mm of slack on the front output flange/bearing .. changed that too. Serviced auto(done at an auto shop) .. went back and got them to fit a shot of shudder fix type additive. Checked rear prop, and donut .. all good.
He doesn't have a CDL at all(ie. no internal mechanism), so couldn't do a test drive with only one prop.

After some time, it then began to developed lockup slip. We initially assumed it was just unlocking far too easily, but then tracked it as torque converter slippage.
Rebuilt torque converter totally fixed the vibes.
Do you have any issues with torque converter not locking? even the most insignificant concern .. like not locking on rare occasions?

So to be sure: you only get the vibes when accelerating from 80-100, or is it there all the time between even at constant speeds between 80-110.
ie. if you sit on a smooth level road at either 80, 85, 90 or whatever, with no additional power requirement .. does it vibrate?

And also remove the (front end of) the rear prop and also the handbrake drum and check for slack in both the rear output flange and bearing(and obviously check for oil leaking).

I personally don't have a road going D2(yet!) but have limited experience with brother's TD5.
I do follow many posts on the D2 forums too tho, and the D2 is reknown for handbrake drum issues causing vibrations .. or more accurately vibrating noises(I think).
Other 'left field' possibilities include stuff like exhaust(eg. broken rubber mount) .. and accessories fitted? watts linkage rubbers .. etc, etc.

Also to be clear on your use of the term 'vibration' .. actual shuddering or noisy(rattling) .. or any combo of either?

The vehicle had no vibrations prior to this being fitted. The original owner got sick of tearing the donut every couple of 4x4 trips. I was curious if anyone else with a GBR Utah prop had balancing issues.