View Full Version : Harrop Differential Problem
A few months ago, I purchased and installed the Harrop cover -
http://www.bmrfabrication.com/gto/Harrop-small.jpg
- for my 2005 6.0 GTO.
Has anyone had this problem with their Harrop cover bushings? It's the left bushing only.
http://www.ls1gto.com/forums/attachment.php?attachmentid=21912&stc=1
I can't remember how many miles I have on the cover, but it's at least 4 thousand miles. I've been underneath the car several times since I installed it and it hasn't been like that so it must have happened recently.......I haven't run anything over. I'm kinda puzzled.
VooDoo
11-10-2005, 09:38 AM
I havent heard any issues with those covers but in the past ive killed bushes like that by overtightening them. Possibly be a cause.
plonkerchops
11-10-2005, 10:00 AM
have yopu tried speaking to Harrop about it ? :eek:
have yopu tried speaking to Harrop about it ? :eek:
I sent an email to the company I purchased it from.
My post isn't meant to degrade Harrop or their products. I just wondered if someone else had experience with this and could give me a little insight. No big deal, right?
I havent heard any issues with those covers but in the past ive killed bushes like that by overtightening them. Possibly be a cause.
Hmmmm. I had thought that at first, however, the bushing has a steel sleeve inside that would prevent that. Good idea, though.
chilly
11-10-2005, 01:45 PM
no names etc
but there is others that have the bushes shot
Although I haven't actually seen any myself, I have heard of this happening before.
I suspect that this happens when there is a longatudinal load put on the bush from the subframe moving forward/backward releative to the body. This would happen if the front bushes in the subframe are wearing prematurley. The rear mount/cover (& bushes) were never designed to take load in this direction. :(
To reduce the occurence, we are modifying the shape of the mount to be tha same diameter as the urethane.
Thanks for the feed-back ... it is paramount to enable our continued development.
:cool:
I suspect that this happens when there is a longatudinal load put on the bush from the subframe moving forward/backward releative to the body. This would happen if the front bushes in the subframe are wearing prematurley. The rear mount/cover (& bushes) were never designed to take load in this direction. :(
Well, I also replaced the subframe bushings at the same time as the cover. Urethane bushings also from the same company. So that rules that out.
nemesis5
11-10-2005, 11:56 PM
just had a look at mine, has travelled around 3,000km's now, still looks new - but i'll be keeping an eye on it now :confused:
Well, I also replaced the subframe bushings at the same time as the cover. Urethane bushings also from the same company. So that rules that out.
Hmmmm ... interesting.
Based on the image posted, there appears to be a "longatudinal" mis-alignment (the mount has compressed into the rear of the bush). When first installed did the mount align without force, or has the mis-alignment developed after installation?
What brand of front bushes (or company you purchased from)?
If they are ours, we will consider sending replacements so that we can examine the currently-installed units to ensure the "right" compound was used.
Hmmmm ... interesting.
Based on the image posted, there appears to be a "longatudinal" mis-alignment (the mount has compressed into the rear of the bush). When first installed did the mount align without force, or has the mis-alignment developed after installation?
What brand of front bushes (or company you purchased from)?
If they are ours, we will consider sending replacements so that we can examine the currently-installed units to ensure the "right" compound was used.
The mount aligned easily when it was installed. I left the upper mount loose until the cover was bolted to it and then tightened the 4 bolts to the body.
The subframe bushings were Harrop also. I purchased the cover and bushings from BMR together. Here's a link to the page showing both products. http://www.bmrfabrication.com/GTO.htm
Please email me via ken@harrop.com.au with your contact details so that we can discuss the best way to assist.
;)
Please email me via ken@harrop.com.au with your contact details so that we can discuss the best way to assist.
;)
E-mail sent. Thanks.
Please email me via ken@harrop.com.au with your contact details so that we can discuss the best way to assist.
;)
Any news on a solution yet?
Although we haven't been able to duplicate the situation on any of the installations we have done or seen, we believe we have discovered some issues that may contribute to the premature wear that you have experienced.
- The route of some aftermarket exhaust systems place the pipes in close proximity to the left side bush. It is possible that the additional heat will degrade the bush.
- The stack up of the body shell manufacturing tolerances does allow for the subframe to be biased to one side/corner. As the torque load is applied to the subframe, it will tend to load the left-rear bush excessively rather than distribute the load as designed.
We are now shipping the kit with two large panel-washers for placement between the mounting bracket and the rear of the bush which will better support the urethane in the rare installations that experience this concern.
We have also re-designed the bracket to incorporate a larger flange for future manufacturing releases.
Thanks for bringing this phenonomon to our attention, and your assistance in solving it.
;)
Any chance that I could get a replacement bushing for that side?
- The route of some aftermarket exhaust systems place the pipes in close proximity to the left side bush. It is possible that the additional heat will degrade the bush.
Stock exhaust
http://www.redgto.com/kb/Attachments/0a31a7f0-82d7-4018-9f34-664c.jpg
with Stainless Works Catback
http://ls1gto.com/forums/attachment.php?attachmentid=16917&stc=1
Doesnt look too close, but maybe. I might have to insulate the pipes at that point.
Your exhaust appears to be fine. I doubt that it will cause any issue.
Please send me an email regarding getting a replacement bush.
joffa
30-11-2005, 09:50 PM
i've got a similar problem with mine, my left hand bush is craked too and i also installed the subframe bushes the same time the diff mount was fitted. this is on a vy ute though.
i've got a similar problem with mine, my left hand bush is craked too and i also installed the subframe bushes the same time the diff mount was fitted. this is on a vy ute though.
Check this thread - http://www.ls1gto.com/forums/showthread.php?t=44805 - for pics and more info.
i've got a similar problem with mine, my left hand bush is craked too and i also installed the subframe bushes the same time the diff mount was fitted. this is on a vy ute though.
Joffa ...
Please call me on 03.9474-0900.
We would like to have a look at your ute, as we have been unable to duplicate the issue.
Thanks ...
joffa
02-12-2005, 10:54 PM
No problem i'll give you a call monday morning.
Cheers.
Steve'sR8
16-12-2005, 06:05 PM
Hi guys,
has this issue been resolved & how effectively does this product control axle tramp. I have a VZ R8 Maloo which suffers from terrible axle tramp, it's embarrassing, perhaps it's my driving but i'm hoping this diff cover will rectify the problem.
Cheers,
Steve.
Hi guys, has this issue been resolved & how effectively does this product control axle tramp. I have a VZ R8 Maloo which suffers from terrible axle tramp, it's embarrassing, perhaps it's my driving but i'm hoping this diff cover will rectify the problem. Cheers, Steve.
Steve ...
I am sure that others on the various forums will be better able to atest to the performance of the Sports Diff Cover, but we get a lot of positive feedback.
There are many instances of fitting the cover only, or the cover & front bushes, which has resulted in the near-elimination of axle tramp. There are also some vehicles that seem to shudder the screws loose from the dash no matter what is done!:eek:
It would appear that it can be somewhat vehicle-specific, but the combination of one, some, or all of:
Diff Cover
Front bushes
Full bush kit
Replacement shocks
will significantly reduce axle-tramp.
And yes ... the "prematurely wearing bush" issue has been resolved, even though it is primarily the result of sub-frame mis-alignment. All kits are now supplied with additional bush support.
:D
Steve'sR8
17-12-2005, 02:52 PM
Thanks for your prompt reply Ken, i'll ask around & perhaps grab one after christmas. Are the subframes misaligned from the factory or does it need to be realigned when the kit is fitted?
Cheers,
Steve.
Thanks for your prompt reply Ken, i'll ask around & perhaps grab one after christmas. Are the subframes misaligned from the factory or does it need to be realigned when the kit is fitted?
Cheers, Steve.
From our experience, and from what others have told me, both.:(
Some 'showroom' cars in the USA have been misaligned, but that may be due to the way they are shipped.
If replacing the front bushes, it is mandatory to align on reassembly.
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