TR4/4A Early TR4 Rear Suspension

[TRDejaVu]

is my choice for getting some attention this winter. The leaf springs came off real easy and I will be fitting the upgraded bushings. I had also noticed that one of the lever shocks was leaking. Which brings me to the 2 questions.

1. If I am going to fork out for rebuilt lever shocks and the links, I am wondering if I should try the TR4 rear tube shock conversion kit instead. Anyone done it, or know someone who has? Pros / Cons (I'm not worried about originality).

2. What should I be doing to the leaf springs while they are off the car?

 

[DougF]

I have the conversion with KYB shocks on my TR6. The ride is firmer than the levers, but I like it better. It's a matter of preference and a little getting used to.
When I remove suspension parts, I generally sandblast or clean the pieces and apply a fresh coat of paint.
Inspect everything as it comes off and fix or replace if necessary.

 

[SCguy]

The TR6 kit is not the same at all. I had my levers rebuilt as no one had tried the kit and I didn't want to be first.

 

[DougF]

Yes, I agree, the kits are totally different. But the end result will be similar.

 

[TR3driver]

But the end result will be similar.

Or not. The TR4 rear suspension is a much different beast than the TR6, with stiffer springs, stiffer shocks from the factory, and a lot more natural damping (friction).

 

[PeterK]

Leaf springs need to be oiled between the leaves. Two methods: 1) is to wire brush the heck out of them paying attention to get the sides nice and clean, or b) disassemble them completely first. Either 1) or b) requires that they be oiled between the leaves to work properly.

I chose method 1) adding some media blasting to clean them thoroughly. Of course, then I had to clean the media from between the leaves. Afterwards, I tipped them on one side and dripped oil along the seams between the leaves and left them to soak for a few days, flipped them over and did it to the other side.

But, if you want to paint them, paint them first.

 

[TR4nut]

Ian-

If you go the route of completely disassembling the leaf springs, I think Teri Ann Wakeman had a good modification of adding thin plastic sheeting between the springs for lubrication/eliminating squeaks etc. Not sure if she has it on here website, I think she posted it once on the Triumph mail list.

 

[TR3driver]

I'm trying a third method: Adding a layer of UHMW polyethylene tape between each leaf.

With the amount of crap, crud & corruption I found between the leaves; even on the ones I disassembled and cleaned myself some 25 years ago then kept reasonably well oiled since then; I would definitely recommend disassembling and cleaning.

 

[TRDejaVu]

So how do they come apart? Do you have to drill out the rivets or can the retainers be spread apart?

Also, my passenger side spring has the extra 2 stub leaves to counter the driver only weight. Keep them or ditch them?

 

[CinneaghTR]

Supposedly, this is THE outfit to rebuild your lever shocks:

https://www.nosimport.com/

NFI, but I am going to go with them when I redo the rear.

Baltimore has a leaf spring shop and I was thinking about going there to have mine refurbished. I figured they might have some tips or tricks from experience. I don't know if you would have a local shop.

Good luck!

 

[SCguy]

That's where I had my shocks rebuilt. Give them a call. They guarrenty no leaks.

 

[TRDejaVu]

What about Apple?

 

[PeterK]

Never heard of nosimport but I had mine done by https://www.applehydraulics.com/ and they did a good job.

 

[TRDejaVu]

So how do they come apart? Do you have to drill out the rivets or can the retainers be spread apart?

Also, my passenger side spring has the extra 2 stub leaves to counter the driver only weight. Keep them or ditch them?

Bump.

 

[TRDejaVu]

Re. what I said above about the 2 extra stub leaves. If the difference was to counter the driver only weight then shouldn't the stub-leaved spring have been fitted to the drivers side. I was chatting this morning with a guy who restores muscle cars and he mentioned that some of those cars had uprated rear springs on the passenger side to counteract the engine torques on high power launches. These cars might not be in the same category, but it got me wondering.

Have these springs been off in the past and refitted on the wrong side or are they meant to be that way? Can I just remove them so both sides are the same?

 

[TR4nut]

Ian-

Need to rethink my geometry perhaps, but I think the spacers on the passenger side make sense - adding them lowers the car because the differential is above the spring. So with a gravity challenged US driver perhaps that would make the car level.

Not sure if my car had them originally, but I've since replaced with Moss springs which are identical on both sides.

Randy

 

[Moseso]

Spring disassembly: Don't drill. Just spread the clips.
I don't think those little spacers on the spring make enough difference to worry about. My TR3 came to me with one "leaflet" on each side. But, yes, the original installation is on the passenger side.

+1 on nosimports (aka World Wide Import Parts) for shock rebuilding. Good work. Good warranty. Easy to work with.

 

[TR3driver]

So how do they come apart? Do you have to drill out the rivets or can the retainers be spread apart?

Also, my passenger side spring has the extra 2 stub leaves to counter the driver only weight. Keep them or ditch them?

Sorry, Ian, I didn't see this before.

I'm not sure if it's the 'right' way, but what I did was to just pry and bend the retainers enough to slip the leaves out, after removing the center bolt of course. They are just mild steel, not nearly as hard as the spring leaves; so not too hard to bend with the spring clamped in a vise and a suitable pry bar.
https://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=1654

Afterwards, I used the vise as a press to force them closed again.

Of course I'm sure there is a limit as to how many times they can be be bent, but this is the second time for this spring and it seems OK.

The spacers go on the passenger side. As noted, because the TRs have the axle above the spring, the spacers lower the car on that side, rather than raising it as with most cars & trucks. The spacers are not essential (TR2-early TR3A did not have them) and were supposedly added because there was some sort of race class where the car had to sit level with the driver in the car.

Eventually I plan to check corner weights, and add/remove shims as indicated.

 

[TRDejaVu]

Thanks to all. I took one spring pack apart using a GS (Graunching Screwdriver) on the retainers. The leafs seem a bit worse than Randall's pics earlier in the thread and there is some deeper pitting near the ends. I had planned to grind them smooth, protect them with some sort of flexible wear resistant paint (?) and then try the UHMW tape.

That is a lot of work, especially considering the loss of material due to pitting, so I'm now wondering whether to just buy new springs from Moss, or wherever. Randy and others, how have you found the new springs to be?

 

[TR3driver]

I'm trying a third method:

Just for clarity and credit where credit is due; I got the suggestion for UHMW Poly from TeriAnn.