TR4/4A TR4 front suspension rebuild advice

[TR4nut]

My 65 TR4 is showing its age in the front end. Does anyone have advice on the following:

Bushings - I was thinking original rubber instead of hard urethane given other comments I've seen on ride quality. Is there an alternate more complexible choice that is close to stock ride but longer wearing?

Springs: I have the 11" or so variety, with no spacer - they are sagging, my stock tire clearance is about 1.5", and frame is only about 4.375" above ground at the front. Thought about stock replacement here also, any other opinions?

I was thinking of going cheap and seeing if I could reuse the trunnions. Some feedback I picked up previously suggested this was going too cheap. TRF has them on sale so I'd like to order before I take everything apart to verify. Do most people replace, or reuse?

TRF is nearing the end of the winter sale - anyone have feedback on their full "magic kit"? Seems like it has everything, but price even discounted is pretty high - makes me think I can do better piecemeal. Any other recommended sources for various suspension components?

Thanks,
Randy

 

[bluemiata90]

I guess the first and most important question is "How long do you plan on keeping this TR4".I just rebuilt my TR3 front end and my thinking was, 40 years old and the original rubber finally needs replaceing. I won't be around for another 40 years, so I went with original rubber. Plus it does ride softer. I figured I plan on keeping my TR3 for and long time and if I went to the trouble of pulling the front end apart, I replaced everything with original, except the steering. I converted my old type steering to rack and pinion. If your rebuilding the front end, I suggest you check your steering flex couplings. After 40 years, I'm sure they need replacing and they are very important. Good luck with your rebuild.

 

[Geo Hahn]

[ QUOTE ]
...40 years old and the original rubber finally needs replaceing. I won't be around for another 40 years, so I went with original rubber...

[/ QUOTE ]

I follow your thinking... but I wonder whether the rubber replacements available are of the same quality as the originals. I would hope so but some seem to think that the replacement stuff isn't as long-lived as what Standard put on there originally.

 

[TR4nut]

I was definitely leaning to rubber, but a pretty respected TR3 owner on another Triumph list mentioned he had worn out rubber after 1-2 years of regular driving. Made me think the replacement stuff isn't quite as good. But I'm not looking to build a racer, I want a nearly original ride but with some longevity. I do plan to keep the car a while, but 40 years from now I might not be driving it!

Thanks,
Randy

 

[DougF]

I would definitely go urethane. The durability is considerably better than rubber.
My feelings have always been that bushings are at pivot points. I do not want to rely on my pivot points to help soften the ride. Leave that job for the springs and shocks.
The more the pivot points move, the sloppier the front end and the handling will be.
My first front end rebuild with rubber lasted about two years. The second with urethane lasted around eight years. I'm currently into my fourth year with nylatron.

 

[RobT]

My own "experiment" in this area was to use urethene on the upper fork bushes and rubber on the lower. The logic here was that the upper rubber bushes seem to wear and distort pretty quickly and so using urethene on the upper end will increase longevity, but by using rubber on the lower fork, I avoid the harshness of urethene all round. So far I am happy with this compramise, although time will tell.

As for springs, I initially installed the TRF supposedly stock length performance springs. This actually raised ride hight about 1-2" above stock, so I switched to their lowered springs, and the rear is about right, but I had to use a 1/2" spacer to get the front right (and avoid the risk of the tires rubbing on the guard.

As for the trunions, once you have everything disassembled, you will have an idea of how much float there is with the ones you have. This is hard to tell before hand because the springs put these under tension.

Hope that helps,

Rob.

 

[Simon TR4a]

My initial reaction is exactly the same as Bluemiata and Geo!
I have had my '65 for 10 years, having replaced all the bushings when I bought the car in order to pass safety inspection.
As I am rebuilding I bought new bushings, poly for the upper ones, rubber for the lower. The upper ones were almost like new, as I had done them with polyurethane the first time, but the lower rubber ones were due for a change.

I do not find the ride harsh with this setup; as Doug says you are simply helping the suspension to move in the intended direction while reducing motion which might occur in other directions.Tyres with a very stiff sidewall or worn out shocks would be a more likely cause of ride problems, in my opinion.
Simon.

 

[trfourtune]

doug,
how do you like the nylatron? i am still debating in my mind which way to go, eurethane or nylatron with a leaning toward nylatron.
rob

 

[TRTEL]

Randy, If you want to go one more step with the nylon or urethane bushings add some grease zerks to them. And cut some channels on the interior surface with a dremel tool. I've had a set on for over 15 years and have gone thru two sets of the outer brass bushings on the TR3 while the inners barely have any play when unbolted from the spring pan. Am now in the process of doing the same to the uppers, which are now urethane.
Tom Lains
TS8651
TS58107

 

[Alan_Myers]

Hi Randy,

I agree with the points about using urethane. They are much more durable than rubber and will help make the handling more precise.

Downsides to urethane include that they sometimes squeek, which would be addressed with Tom's suggestion. There is special grease for use with urethane bushings. It can just be wiped on, or use a zerk as Tom suggests so that it can be greased again later.

Another "problem" with urethane is that it will make any other faults in the suspension more obvious. Things like bent arms or misaligned geometry will be more obvious. Of course, using rubber just masks the problem, it's still there.

A third consideration, expect a little more road noise with urethane bushings. Exactly how much depends upon the hardness of the particular bushings you use.

Speaking of which, it's not been mentionted that urethane is available in a variety of hardness or durometer ratings. Some can be close to the same as the original rubber, most are a little firmer, some are a lot firmer. It might pay to shop around. I think Superflex is one brand that comes in different durometer, but I'm not that knowledgeable about TR urethane options. Seems most U.S. vendors just offer "rubber or urethane" kits with no further info about the urethane. I see some of the British vendors offer choices of TR kits in various urethane hardness. I've got a set of softer "offroad" urethane bushings for my Land Rover, not yet installed. Rover vendors do tend to offer choices.

Rather than TR-specific kits, urethane bushings can be bought locally in "standardized" sizes. All the applications on TRs can actually be found amoung standardized sizes, except for the rather odd-shaped mounting bushings for OEM sway bars. One reason to buy this way, is that some local tuning shops in my area are now offering a selection of hardnesses, might be in your area too.

You asked about nylatron and I'll be interested to hear Doug's response. In general, nylatron is harsher than urethane and most would consider it a "race only" option. In fact, there are nylatron bushings already being used on the lower/inner a-arm joints of TRs. Those are original to the cars. With minor modifications, these could be used at the upper/inner joints, too. But, I'm sure that would make the ride harsher. Nylatron will be considerably noisier, too.

I've now got urethane installed on my TR4: front upper suspension, upper and lower front shock mounts, plus both the mountings and end links of the front sway bar. But, I can't really say how I like it yet, since the car isn't back on the road yet. I did use rubber on one end of the sway bar end links, to allow about half the normal movement before the bar becomes effective that a "stock" sway bar setup would have. I'll try it that way and can always swap to full urethane or full rubber, to tune the sway bar action a little.

One last thing I think I'll change is to eliminate the rubber bushings at the TR's rear shock links. I plan to replace those stock links with custom rod-end type (aka rose joints in England). This makes the shock more effective, with no slop in the end link, but tends to transmit more road noise, too.

In fact, rod-ends can also be used on the front suspension and/or sway bar. However, this is definitely a full race type suspension and would be very harsh and noisier. (Note: rod-ends you find might in your local hardware store probably are not up to the task... racing suppiers such as Pegasus, Summit, Jegs and Racer Parts Wholesale offer stronger, often Teflon-lined ends that are appropriate for suspension use, but are pricey.)

To summarize:
- rubber... mushier feel, don't last long, but forgiving of some suspension misalignment, softer riding and quieter.
- urethane... more of a sports car feel, a little harsher and noisier, possibly will squeek, but are available in different hardnesses.
- nylatron... more of a race car feel, harsh and noisy, but even more precise handling than urethane.
- rod ends... a full race setup, very precise, but very harsh and noisy, expensive, will require custom installation, more prone to wear and will need more frequent service.

One thing I do get a kick out of is the urethane "upgrade" spring bushings being offered from some vendors. These are the pads that go at the top and bottom of the coil spring, primary purpose to prevent direct metal-to-metal contact and noise. Well, the 40 year old rubber ones on my TR had hardened to urethane-like consistency, so I happily reused them!

/ubbthreads/images/graemlins/cheers.gif

 

[KVH]

I just rebuilt nearly my entire front end. TR4A. I agree with the comments above, but would add: It's the uppers that seem to distort and wear out quicker. Mine, after only short while showed stress and even a "split" on the outer ears. Mine are all original rubber. The car rides like new, absolutely new. Quiet, soft and tight. All said, I'd probably try urethane on those uppers if I could do it over.

 

[TR4nut]

Just went to upper management (my spouse) to request clearance for funds and to my surprise funding was approved. I think I will buy the major components from TRF and Moss before their sales dry up this week, but defer most of the bushing decision until later.

I noticed this weekend that the rear springs are pretty tired too - after I pulled into the garage the car was listing pretty good on the driver side. I am a bigger boy than I used to be (~210 lbs) , but I don't want to be seen driving a car that is tilted if I can help it!

So it looks like new coils up front, new leafs in the back, both stock rated, and a bunch of other stuff to hold it all together. Thanks a lot for the feedback - it helps. I am intrigued by the thought that there are different durometer rated bushings out there - that makes a lot of sense and I am surprised it is not advertized by the big vendors a bit. Right now my thoughts are to use urethane for the pivot points, and probably rubber for spring pads, steering rack mount,etc. to try to damp out any harshness.

 

[KVH]

I meant to tell you: I replaced the tie rods, ball joints and front springs. Definitely do replace those springs. Major difference on my car. I bought the stanard Moss "red" springs. I may do the rear springs, too.

 

[trfourtune]

revington uses superpro urethane bushings from australia. these have grooves in them to hold lubricant. there is a supplier in the USA. if i go urethane, these are the ones i'll use.
rob