Coilovers destroying my drive shafts

Question

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

Answer 1

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.

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):

Non-complementary angles (BAD):

3. 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.

Perpendicular:

4. 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.