[mech65]

I have a strange vibe coming from ( what feels like ) the differential. Does a driveshaft go out of balance easy? Is there a test I can do to tell if is my Diff.

I have changed my: tranny tail bushing, center support, U joints, All rear bushings (to poly). It is very strange. It doesn't usually do it when cold, most noticable during breaking. Vibe between 40-50 mph. I don't think it is the drive shaft because it doesn't do it at all speeds.

I am baffeled ..... Do differentials usually go out? I have 135,000 miles on it.

 

[Tech]

Did you mark the driveshaft before you pulled it apart to do the u-joints?If they weren't put back the same it will cause a vibration.It could also be a bad center carrier support.You don't have a bad tire do you?

 

[mech65]

I did mark the drive shaft. The vibe was there before I did all of this work. I rotated my tires. Still there.

I am baffeled. That is why I'm concrened it is my differential, what are your thoughts about that?

BTW I changed my center carrier. At this point I'm going to check my rear rotors and maybe have them turned or replace.

Thanks

 

[Tech]

Check the rotors first.I have never seen a problem in the diff. on these cars.

 

[mech65]

Thanks tech. I'm going to check the rotors and replace the bearings in the rear.

Its good to hear that the Diff. is (or aleast may not likely) not the problem.

 

[Tech]

Let me know how it goes.

 

[Don]

I have a 1988 240 GL with the same vibration as described. I did have the u-joints replaced, but that was because of the vibe. I don't knoe if the mechanic had marked the driveshaft or not. I suspect not. I live in a part of Indonesia where the knowledge of Volvos is limited, and my mechanic here thinks the driveshaft is 'bent' and is going to try to straighten it for me. Now I am concerned that it may not be bent at all, but just put back in a different position. My question is, how does one find the original position, and if that can be done, will my vibe be eliminated?

 

[Tech]

The easiest way to fix it is to have the driveshaft balanced.If he put it together wrong then it might be out of balance.

 

[mech65]

Tech,

I pulled the rotors off sat. Turned them on a tire machine and they are straight. Next I guess will be the rear wheel bearings. I had the bearing but no seals so I didn't tackle the bearings. Plus it was getting late and the bearings look like they could be a pain in the A**

What are the symptoms of bad bearings?

I'm still nervous about the Differental.......

Thanks

 

[Tech]

Most signs of bad bearings are a humming noise.

 

[MiRo]

mech65 and Don

do you have a problem all the time while you're driving or only when you start?

 

[mech65]

It doesn't do it starting out once I get up to speed and very noticable at 40mph. Also while heavy breaking.

I would say that it is a high frequency vib. that is the only way I can explain it.

 

[mech65]

Tech
I looks like you have access to volvo manuals.

Can you post a good picture of the Rear axel bearing break down?

Thanks

 

[Tech]

I don't have the access to the Volvo manuals at this time.
My other book doesn't have any good pics.

I wish I could help more but at the moment I can't.

 

[mech65]

Have you replaced the Axil bearings before? I have access to a press and a mix of pullers. Is this a DIY job? Any do's and don't would be greatfull.

 

[Tech]

If you have access I don't see why not.Just be careful installing the new bearings.Make sure you push on the solid part of the bearing.I have not done it but seen it done before at the shop.Not very often though.

 

[mech65]

Thanks I'll let you know how it turns out.

 

[Tech]

I will be waiting to hear from you.

 

[Don]

The vibrating happens all the time, but only at around 40kph and around 80kph. I found a mechanic who "straightened" the driveshaft. Now it's better, but not satisfactory. He says I need new u-joints (again). So I've sent off to Sweden for the parts, there being none in exiostance in Indonesia. I hope this fixes it. Should take 3 weeks for the parts to arrive.

 

[mech65]

How does you drive shaft get bent? I'm curious, as our symptoms sound very similar. I may take mine in to get balanced then.