Lever shock maintenance

[John_Mc]

I recently refurbished the front suspension on my TR6 with all new rubber bushings (urethane on anti-sway bar) and new ball joints and trunnions. I did notice some immediate improvement, but not on the scale I hoped and I suspect it's because I have done nothing to the rear suspension. I still get a lot of rattle noise from the rear and even some "sliding" sensation over bumpy sections of the road. I'm sure the rear suspension needs work since in the 5 years and 21,000 miles (450 over the weekend!) I've owned and driven the car, I personally have done nothing to the rear suspension (except replace the right side shock-to-trailing-arm link. I should check my service records to see if the rear shock oil was checked when other service was done.). As I said, I'd like to tackle the rear suspension, but I'm not sure how much time I'll need and so I'm thinking I should just wait until the summer/fall driving season is over. In the meantime, I'm thinking that I should check the lever shocks to make sure they are functioning to the best of their capacity. So my questions are:
1) How do I check shock oil level/function?
2) If oil is needed what kind do I add for optimal performance? I recall reading posts about adding different viscosities of motorcycle shock oil to improve handling
3) For a first timer, how much down time would I be looking at to refurbish the rear suspension? (new bushings)
and finally
4) How beneficial would a rear anti-sway bar be?

This is a load of remedial questioning, I know. Thanks in advance for any advice.

 

[MGTF1250Dave]

Aloha John,

You can do a quick check of theperformance of your shocks by pressing down on the corner of the car and letting go. the car should move back to original height and stop, if it continues to bounce you shocks and perhaps links need attention.

The shock oil should be up to the bottom of the threaded filler hole in the shock body. If not top it up with shock oil that is available from most of the LBC part suppliers. He is a link to illustrate shock oil:

https://www.mossmotors.com/Shop/ViewProducts.aspx?PlateIndexID=31448

Some people use motor cycle fork oil.

I use a wood working glue applicator to add shock oil. These are plastic and look similar to a hypodermic needle. It keeps the fluid from spilling and is smaller than the original bottle. It also allows you to remove some oil if you over fill the shock. There needs to some air space in the shock to allow the oil to expand as it works and warms up. Also check to make sure the mounting bolts are tight.

I am not very familiar with the TR6 rear suspension so I can't advise on rebuild times. I have heard that the trailing arm attachment points on the frame are prone to working loose or breaking. I sure one of the TR6 guys will have lots of good advice for you.

Regarding sway bars, many posts have suggested that if you use a front sway bar, a rear sway bar should also be used.

 

[BryanC]

If your shocks are bad, fixing them can make a very big difference. I'm not sure that adding fluid or changing fluid type is all that will be required to fix them. My TR6 was very rough and rattly over bumps. In a straight line, over a rough spot, the back of the car would move sideways a foot or so. It was awful. About a week ago, I replaced the rear shocks and it made a huge improvement. It stopped the back of the car moving around over bumps and everything rattles less (I still need to fix the window channels but it's better now). I went with tube shocks but I'm sure a good set of lever shocks would have made a similarly big improvement. I think a rear sway bar can improve handling but fixing the shocks will probably make a bigger difference for you.

Bryan

 

[brent615]

This was helpful to me https://mywebpages.comcast.net/rhodes/shock.html

Also, I found on eof my rear shocks had worked loose. The bolts were halfway out! I took them all the way off, refilled them with Harley Davidson fork oil (leaving a little space for air) and bolted them back on WITH lock washers.

 

[Tinster]

John-

Here is decent "how to" that shows you step by step
how to refurbish the rear suspension-- except for the differential mounts..

Pages 6 and 7 deal specifically with lever shocks.

If you get stuck, PM me. I think I could do this one blindfolded.

d

 

[DougF]

You do not want to put on a rear sway bar without upgrading to a heavier front bar. Likewise, you don't want to upgrade the front without doing the rear.
The amount of time to do a rebuild of the rear is dependent on how much you want to do.
You have to drop the diff to change bushings. Inspect the frame before doing this for cracks at the mounting pins. If you don't weld, you can drive the car to a repair shop before you start the project.
Check your rubber brake lines, emergency brake cable, ujoints, splines, etc. You will want to lube everything as you put it back together.
You may also want to paint everything.

 

[Brosky]

<div class="ubbcode-block"><div class="ubbcode-header">Quote:]You do not want to put on a rear sway bar without upgrading to a heavier front bar. Likewise, you don't want to upgrade the front without doing the rear. [/QUOTE]

Doug, I agree. I think that the key here is matching both with torsional rates designed for the exact car and to be fit together as a set.

 

[swift6]

<div class="ubbcode-block"><div class="ubbcode-header">Quote:]You do not want to put on a rear sway bar without upgrading to a heavier front bar. Likewise, you don't want to upgrade the front without doing the rear.

Doug, I agree. I think that the key here is matching both with torsional rates designed for the exact car and to be fit together as a set. [/QUOTE]

While I agree with the not adding a rear sway bar without increasing the diameter of the front sway bar, increasing the diameter of the front without changing anything else will only cause a slight bit more understeer which is not near as dangerous as the oversteer induced from a larger rear sway bar.

The point Paul brings up about torsional rates is also very important. Just consider that the coil springs one puts in the rear can also greatly affect this area. Stiffer and lower springs raise the torsional rate and a larger front swaybar can help balance that even without a rear sway bar.

I have been able to achieve a fairly balanced set up on my TR6 with 'Fast Road' springs, a 7/8 front sway bar and careful attention to air pressure in the tires. All without sacrificing the limited ground clearance, from the lower springs, that accompanies most of the rear sway bar set ups available for TR6's. Maintaining a slight bit of understeer for better pedictability/safety.

Like many things in life... there are multiple ways to address individual issues...