Restoration-Mini

Technical Forums => Maintenance and Modifications => Topic started by: Coalhod on December 29, 2021, 03:15:23 PM

Title: Rear subframe/trailing arm problems
Post by: Coalhod on December 29, 2021, 03:15:23 PM
Hello;  Had some strange handling where on left hand turns the car would want to step out from the right rear side.  Decided to remove trailing arms and compare as per 7 Enterprises blog and the arms are "pretty close".  I did find that the right side arm was on a bind and found the trailing arm pin took a lot of effort to turn so it looks like rebuild time.  Also, when checking tracking I had over 3/4" total toe in at the rear and installed MiniSpares MS 73 brackets which brought that to 3/16" - would like to get a little closer to 1/8".  On inspection of the subframe where the trailing arm pin bolts at the inner side the 1/2" hole is slightly wallowed out so I have read elsewhere welding a washer there should cure the problem.

Winter projects!

Title: Re: Rear subframe/trailing arm problems
Post by: MiniDave on December 29, 2021, 03:34:12 PM
A stuck trailing arm pin will definitely affect the handling - ask me how I know!   ;D
Title: Re: Rear subframe/trailing arm problems
Post by: 94touring on December 30, 2021, 11:54:35 AM
Rear toe should be 1/16" to 1/8" total (in) fyi.
Title: Re: Rear subframe/trailing arm problems
Post by: Coalhod on February 01, 2022, 07:16:51 AM
Hello;  FWIW an update on doing this repair.  I had originally done it using a brake cylinder hone on the bush (wrong) and oddly enough another local Mini owner had the correct 13/16" reamer to do the repair.  Anyway when all was said and done the trailing arm pin turned with little effort by hand!  Not so previously!

The other alternative and probably a better way to go is to exchange the arm(s) with one of the major Mini parts suppliers.  I have found a price discrepancy on both U.S. and British suppliers for the exchange arms and the returned arms have to be straight (serviceable) which makes sense so the price for a bad (bent) arm would be as an outright cost.  Seems U.S. suppliers are much costlier for the same service.
Title: Re: Rear subframe/trailing arm problems
Post by: MiniDave on February 01, 2022, 09:23:50 AM
Good to know you got it sorted....the problem for me with doing an exchange with one of the suppliers in England is the cost of shipping.
Title: Re: Rear subframe/trailing arm problems
Post by: 94touring on February 01, 2022, 10:53:27 AM
You could always buy the fancy alloy arms like I have!  Big weight savings on the suspension.
Title: Re: Rear subframe/trailing arm problems
Post by: cstudep on February 01, 2022, 11:09:20 AM
Quote from: 94touring on February 01, 2022, 10:53:27 AM
You could always buy the fancy alloy arms like I have!  Big weight savings on the suspension.

Do they not use the "reamed bushing" method or is it just because they are new and all that is already done? Wasn't sure if they use bearings or something different in that area since they obviously have total control of their casting I suppose they could do just about anything they wanted.....within reason of course since it still has to work in place of the standard part.
Title: Re: Rear subframe/trailing arm problems
Post by: 94touring on February 01, 2022, 01:13:21 PM
They use the same bushings. They do come pre reamed though too.