I have a set of Coilovers on my car and it's lowered by about 45-50 mm all around, the driveshaft bearings are lasting about 4-5 months on each side before having to be replaced because of the angle of the driveshaft due to the car being lowered.

The oblivious solution would be to raise the car up to factory spec but I would like to avoid that if possible as the car handles considerably better with the lower centre of gravity.

Is there any way of potentially upgrading/strengthening the driveshaft and bearings or somehow changing the angle of the driveshaft without raising the car ?

Car in question is a volvo c30 D5

  • 1
    move the final drive up / down to compensate for the change in angle - the effects of this should have been considered at the outset... – Solar Mike Aug 24 '17 at 16:08
  • Is it the drive shaft (tranny to differential) or axle shaft (differential to wheel)? I think I know what might be going on, but will wait until I'm not in my phone to answer. – Pᴀᴜʟsᴛᴇʀ2 Aug 24 '17 at 22:04
  • @Pᴀᴜʟsᴛᴇʀ2 It's the drive shaft - tranny to differential – scriptss Aug 25 '17 at 10:07

What I'm going to say applies to both drive shafts on an independent rear suspension (IRS) or with a drive shaft going from the transmission to the differential. There are several different things you need to consider when dealing with a pair of u-joints, all of them having to do with their relationship to each other.

  1. The drive shafts should be clocked the same to each other on a drive shaft. In the following picture you can see the yoke on both ends are right in line with each other. If you don't orient them this way, you're going to get vibrations and the u-joints will wear out fast. enter image description here

  2. Each end should have complimentary angles to each other. If they are not complimentary, again vibrations and wear occurs to the joints. These have to be pretty close to not incur these issues.

Complementary angles (GOOD):

enter image description here

Non-complementary angles (BAD):

enter image description here

  1. The yokes should not be exactly perpendicular to the drive shaft when attached to the diff/tranny. The reason for this is you need the u-joints to move a little bit so the grease is moved around inside the bearing caps. If they are straight, portions of the bearings will dry out causing them to wear out. You don't need a lot of angle, just a bit ... probably 2°+ will do you. Just something to keep the needle bearings moving all the time.


enter image description here

  1. Differential to drive shaft angles too great can be an issue as well. The u-joint can stand quite a bit of angle, but if you have too much angle it will start to bind. You want to be off of that binding angle by about 5° with the suspension at full extended travel. This gives you a bit of leeway so it should never end up binding or even coming close to binding.

If any of these things describe what you have it could be why you are blowing through u-joints. You just need to adjust the alignment of the u-joints to allow it to function correctly and not blow them out.

  • When you say "pretty close", how much tolerance is there? – bishop Aug 25 '17 at 3:20
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    This explained it really well, Going to get it into the garage tomorrow, replace the bearing again and then adjust the alignment as you mentioned, Thanks for the really clear answer! – scriptss Aug 25 '17 at 10:10
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    @bishop - Unless someone knows for sure (because I don't), I'd not let it be more than 1° difference between the two. Really, the closer you can get it the better. Perfect at 0° difference is best. The only time you may not want it exact from transmission to differential is when you may want some difference for performance purposes. Having -1° to -2° on the differential puts it at 0° under hard load and acceleration (there's a name for this and it's eluding me at the moment). If you aren't drag racing the vehicle, you really don't need this. – Pᴀᴜʟsᴛᴇʀ2 Aug 25 '17 at 12:00

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