Trailing Arm Bushes - Help - Too Many Choices

[RobT]

As I have the diff out (see topic: "Expensive sound coming from rear end" Warning, contains graphic photos of broken pinion gears that may be disturbing for sensitive readers), I thought I might as well replace the u-joints and T/A bushes while I'm waiting for the diff rebuild.

I wrestled out the old rubber bushes, and am ready to choose a replacement, but the choices are numerous. Here are the four I have found so far with the pros and cons as far as I can tell:

1) Stock rubber - provide good noise and vibration isolation, but wear out and allow the suspension to flex.

2) Polyurethane - stiffer than rubber, last longer but will transmit noise and vibration (do these squeak?)

3) Prothane - stiffer again, more vibration & noise transmission, need teflon grease to keep quiet

4) Goodparts Nylatron - stiffest of the lot, requires quite a bit of set-up, and a grease fitting on the T/A pivots.

Did I miss anything here? Do folks have an opinion on the best setup, and if I install the Prothane or Nylatron bushings, do I risk exposing more stress on the suspension and frame than it was designed for?

TIA

Rob.

 

[DougF]

What type of driving do you do? Sunday cruising or Sunday auto cross.
Personally, I wouldn't use rubber regardless of what type of driving I'm doing. Reproduction rubber parts are terrible, and these bushings are no different.
Some complain that urethane squeaks. I never had that problem in the ten years I ran them on my car.
I have no experience with prothane.
Some feel that nylatron is too rigid, that the ride is too harsh. I like them. Yes, you can feel potholes more acutely. But at the same time, I don't want my bushings to work as shock absorbing parts, they are pivot points.
The ride quality in my TR6 with nylatron bushings, GP springs, aluminum steering rack mounts and upgraded sway bar is no rougher than the ride in my stock TR3.
I've always felt the TR6/250 was a little soft in the rear. I would go with the nylatron #1 and next choices in descending order.
When I ran rubber bushings in the rear years ago, under heavy acceleration the rear end would bump to the side slightly when I'd shift. This problem was solved with the upgraded bushings.

 

[YankeeTR]

I like rubber...I would think that some of the replacement rubber bushings would be of better quality than others.

I re-did the suspension in TS74011L back in the mid-90's and used rubber. I never had a complaint with the product (TRF). An early TR has enough 'driver input' through the suspension that I don't feel it needs anymore than stock bushings provide. A stiffer bushing also is harder on chassis parts and welds...the rubber is a 'shock absorber' for all of the susupension components.

Perhaps a call to TRF might help you decide. Charles or John have always been pretty honest with their answers to my questions...whether you buy from them or not. Moss has been helpful, to but the folks I've talked to haven't been as informed on technical matters as TRF.

A call to Victoria British would be a waste of time...IMHO.

 

[Tinster]

Rob,

The entire rear suspension in the Crypt Car was shot.
I replaced everything. I installed the rubber T/A bushings,
regular coil springs with rubber seats and refurbished the
original Armstrong lever shocks. I was well satisfied with
the ride.

Now I have a busted T/A (Thanks again DPO Pedro, you SOB)
that must be replaced. I have already ordered the new
stock rubber bushings for the T/A soon to arrive.

My vote is stay stock-go rubber.

Once you've switched out T/A bushings the first time,
the next go around will be a piece of cake.

d

 

[rooster]

Hi,

I would stay away from nylatron. You'll feel every little ripple and crack in the road. Ask me how I know!

If you are racing then they are probably the best thing to get. For faily driving I'd go with one of the others.

Cheers

 

[RonMacPherson]

While you've got it apart, I recommend you go with the upgraded ujoints. Can't remember the name or the application(US farm/truck rig, less expensive than some who sell for TR upgrades) For the TA bushings, rubber or softer poly. Poly from a variety of suppliers, can be purchased with different shores(hardness). Poly should last darn near forever(lot longer than the rocker panels) on a TR6. Two things I have found. Use a good silicone lubricant(grease) when applying them, on the pivot points as they can(not always, but often) get noisy. Nobody likes a squeak 2K miles after a rebuild. And if you do wind up upgrading to poly for the diff brackets, make sure you're reinforced on the frame.

 

[swift6]

Poly T/A bushes are one of the easiest and most effective suspension improvements for a TR6. The rubber bushings allow too much flex and deflection in corners causing a very unstable feel while hustling through corners. The polys (or better) keep the T/A's better located and much more stable. The T/A bushes won't change the ride feel as much as polys in the front suspension will. Just be sure to use a good silicone gease when installing them (as suggested above) and that should take care of any squeaks.

The best set up now, for all out performance handling, are a roller bearing design that a few places in the UK are making. More precision is needed on set up but pays off big time in handling.

 

[RobT]

Thanks guys for all the good advice.

My TR is mostly a "Sunday Driver", so I think I will go with the Polyurethane bushings. These seem to be a good compromise, and offer longer life than the rubber. I can always swap back if these feel too hard. As Dale points out, having done it once, the second time is easy. I'll look for some silicone grease to lube up the poly bushes when they go in.

Ron - I installed the "Nepco" brand heavy duty U-joints from Goodparts on the prop shaft. I plan to replace the half shafts with a CV conversion at some time in the future so left these (they all felt fine) but did re-greased the sliding splines, replaced the rubber boots etc. The hubs also felt fine - no slop at all there.

Rob.

 

[Tinster]

Rob,

Don't forget to make your own
pull me/push me T/A bushing tool.

https://rides.webshots.com/photo/2334393360085748235JwvnmB

 

[RobT]

Thanks Dale - yes I made up something similar for the steering column bushes that I used again for the T/As. Useful stuff that threaded rod.

Rob.

 

[Tinster]

Rob,

I'll probably have mine installed before your
parts arrive. A certain person, who will not be named,
has threatened my life if I do not author and post a
technical "how to" article (with many photos) on the
subject of "procedure for changing out trailing arm
bushings".

I admit to being a pretty dim bulb when it comes to auto
mechanics but I take good photos and am a decent wordsmith
of sorts.

If you've never tackled this T/A task before, my tech piece
article might be a useful reference for you. If you have
done it before, then why not fly over and install mine to
get your install technique down pat???

d

 

[RobT]

Hi Dale:

Well its going to be sunny and in the 70's here this weekend ('bout time!), otherwise I'd be down to PR like a shot.

I hope your "how to" will include the best use of situation appropriate profanity in the step-by-step instructions. I have always felt the use of profanity is an important but too often ignored part of British car repair.

Anyway I look forward to seeing it.

Cheers

Rob.

 

[Tinster]

Yes, I too have found it helps me install
things on Crypty.

It's usually "That &^^*($#%$ DPO Pedro!!"

d