How to remove long upper diff mount bolt - Imperial S3, DD
Discussion
I'm trying to remove the diff and have everything apart other than the long upper bolt.
It is semi-seized in the rubber bush on the drivers side next to the bolt head.
The diff is free to rotate back and forth on the bolt and I can get the nut off no problem., but it takes a breaker bar to get the bolt to turn in the bush and when I feel the bush housings after good amount of effot trying to turn it, it's the bush / chassis housing on the right that feels hot after a few turns which is a real effort.
I've tried penetrant and putting the nut back on the other side to 'persuade' it, with the air hammer and also tried my big impact gun on the bolt head, but the rubber bush absorbs all the shock energy preventing progress.
A friend just came round and we tried the air hammer whilst I turned the bolt from the other side to see if we could make progress whilst it was turning in the bush, but again, it didn't want to budge at all.
It's quite an interesting one as with enough effort, i.e a tube on the end of the breaker bar, I can get it to fully rotate and have done perhaps 20-30 full rotations of the bolt now through the course of the afternoon (my arms are about to drop off) but it's just not getting in looser and won't displace laterally no matter what I try.
Anyone come across this before or have any ideas? I was thinking heat, but imagine anything hot enough to soften the rubber bush would also damage the powder coat on the chassis and I really don't want to do that as it's all mint.
Any thoughts?
It is semi-seized in the rubber bush on the drivers side next to the bolt head.
The diff is free to rotate back and forth on the bolt and I can get the nut off no problem., but it takes a breaker bar to get the bolt to turn in the bush and when I feel the bush housings after good amount of effot trying to turn it, it's the bush / chassis housing on the right that feels hot after a few turns which is a real effort.
I've tried penetrant and putting the nut back on the other side to 'persuade' it, with the air hammer and also tried my big impact gun on the bolt head, but the rubber bush absorbs all the shock energy preventing progress.
A friend just came round and we tried the air hammer whilst I turned the bolt from the other side to see if we could make progress whilst it was turning in the bush, but again, it didn't want to budge at all.
It's quite an interesting one as with enough effort, i.e a tube on the end of the breaker bar, I can get it to fully rotate and have done perhaps 20-30 full rotations of the bolt now through the course of the afternoon (my arms are about to drop off) but it's just not getting in looser and won't displace laterally no matter what I try.
Anyone come across this before or have any ideas? I was thinking heat, but imagine anything hot enough to soften the rubber bush would also damage the powder coat on the chassis and I really don't want to do that as it's all mint.
Any thoughts?
Guessing you've already thought of this but just in case... is the diff supported by something other than the long bolt? I.e. a jack under the diff itself or the other bolts installed loosely?
From your post it sounds like the weight of the diff on the long bolt is preventing it from being withdrawn, and as you've seen, the bush takes up any lateral impact when "persuading" the bolt.
From your post it sounds like the weight of the diff on the long bolt is preventing it from being withdrawn, and as you've seen, the bush takes up any lateral impact when "persuading" the bolt.
Fair point, but the diff is not heavy and the rotates feely on the bolt. Manipulating it and transferring any weight makes no difference.
When I turn the bolt with the breaker bar, I can hear the rubber bush creaking under the load.
I think I might need to fabricate a puller/pusher type fixture to force the bolt through from the nut side, almost like the old fashioned slim line ball joint splitters and 'pull' against the shoulder of the bush housing, winding a bolt through the fixture to push against the end of the long bolt.
When I turn the bolt with the breaker bar, I can hear the rubber bush creaking under the load.
I think I might need to fabricate a puller/pusher type fixture to force the bolt through from the nut side, almost like the old fashioned slim line ball joint splitters and 'pull' against the shoulder of the bush housing, winding a bolt through the fixture to push against the end of the long bolt.
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