Part 3 Trailing Upper Arms

The rear axle is connected to the body of the car by a four-link system and the rear springs. The link system comprises two upper and two lower trailing radius arms. Most problems occur with the lower arms in relation to excessive wear on the bushes. Much has been said, and written, about the relative merits of hard and soft bushes. I have tried both with V8 conversions and my own 8 and have come to the conclusion that it is a matter of personal preference. Hard bushes transmit noise and vibration from the drive train (particularly with coupes). Soft bushes can induce 'wind up' on hard acceleration with the V8 and will wear out more quickly. A compromise is to fit a soft front bush and a hard rear one. As my 8 only does a maximum of 3000 miles per year, and I like comfort, I have opted for soft bushes all round.

Post article - I have been advised that a third type of bush is now available for the trailing arms. For a number of years, yellow superflex polyurethane bushes have been available for Dolomites, Triumph 2000s, Stags and the like. Now they are available for the TR7 and 8. As I understand it, they are somewhat softer than the hard bushes currently available and have a much longer life. Also they are much easier to fit. The centre steel bush can be removed before pressing the main bush into the arm and then replaced without much difficulty. The only downside is that they are approximately 50% more expensive than the standard hard bushes. A set is being used on a TR7V8 FHC and I understand that there is no increase in noise levels on the original soft bushes. Rimmer Bros. have included them in their price list and I believe S&S are also offering them. If anyone has had first hand experience of fitting these I would be very interested.

Following the same pattern as the previous articles, all the parts should be available before commencing the strip down. Parts required:

Lower Arms
a) 2x front bushessoftpart no. ULC1579 (Unipart)
hardpart no. ULC1580H (Rimmers)
b) 2x front bushessoftpart no. ULC1580 (Unipart)
hardpart no. ULC1580H (Rimmers)
c) 4 x 7/16" UNF boltspart no. BH607241 (Freight Rover)
d) 4 x 7/16" UNF Nylok nutspart no. NY607041J (Jaguar)
e) 8 x 7/16" washerpart no. WM803
Upper Arms
a) 4 x bushespart no. UKC5514
b) 4 x 7/16" UNF boltspart no. BH607241 (Freight Rover)
c) 4 x 7/16" UNF Nylok nutspart no. NY607041J (Jaguar)
1 x bottle of washing-up liquid
1 x bench vice

NOTE: I have included all the nuts and bolts as they may have to be replaced after removing the arms.