Lever Shock Diagnostics?

[Tinster]

Before the TR up and died, I was attempting to identify and fix the rear end bottoming out and making loud crunching noises over the smallest of bumps or when I pushed down on the rear while parked.

I am making repairs/replacements as I can, while the car is dead in my garage- so no road testing is not possible.

In rear end I have already replaced:
Lever shock mounting bolts (4)
Trailing arm bushings(4)
Diff mounts (4) and fixed the broken RF mount bracket
Refurbished diff
Replaced lever shock link bushings(4)
All diff and drive trane oil seals replaced
Rehung exhaust system with correct hangers
Connected emergency brake cables
Replaced all bumper mounting bolts
Tightened and or replaced every nut/bolt I could see
Installed spare tire hold down assembly
Installed new spare tire cover board with
sound deading carpet strips

The day the TR died it was still bottoming out and making crunching sounds.

Last weekend I completed replacement of both rear coil springs with the TRF upgraded sets. One exist. coil spring had no top seat rubber. Direct spring to frame contact.

The cars sits 1 1/4" higher now and is not on so obvious a slant to one side. No crunching noises when I push down on the rear.

Is there a way to test the lever shocks while the car is in my garage?

It would give me something positive to do and I can't think of anything else that might cause the car to bottom out so easily. I think I have now replaced everything in the suspension system except the shocks? I miss anything obvious?

Thanks as always,

Tinster in very rainy Puerto Rico /ubbthreads/images/graemlins/patriot.gif /ubbthreads/images/graemlins/patriot.gif

 

[gjh2007]

First thing you need to do is be sure there is damper oil in the shocks. A motorcycle fork oil should work. If there is oil you may need new valves, or a complete rebuilt shock. Do you notice any staining around the lever arm where it connects to the shock body.

Also, did you check the rubber bushings on the shock links to the control arms?

 

[Alan_Myers]

Hi Tinster,

Gary has given you some good guidelines.

There's a strong possibility the missing rubber spring seat was the source of your noises. Since you are working on a TR6, I'd also comment that the original springs were considered too soft by many people, Triumph seemed to be trying to meet U.S. consumers' demands for a cushy ride even in a sports car. So I'm not surprised to hear they are bottoming out. TR6 tend to "squat" on acceleration, with stock rate springs, even when the springs are brand new and not sagged from 25 years of use. Shocks won't help much preventing bottoming, that's the springs' job.

TRF's usual "upgrade" springs do raise the ride height of the car a bit more than stock. Some folks like that, others don't. For sake of handling, lower is usually better than higher, and these are sports cars that are supposed to handle tight twisty corners well, after all.

There are other upgrade springs around, I think even TRf might offer a more standard ride height, if you want the car to sit more "normal" or even lower it a little (the latter would best be done in combination with front lowering/upgrade springs at the same time). Last time I looked in their catalog, TRF was offering custom spring spacers in several thicknesses, to fine-tune ride height when using any of the lowering springs (but most likely *not* with their usual upgrade springs that raise ride height!).

Also, do you have anti-sway bars? Front? Rear? Both? If so, their end links or mounting bushings can get old and give way, might lead to some noise. (BTW, a front sway bar around 3/4" diameter and a rear about 5/8" is a fairly common setup on the IRS TRs. Some use only a front bar, but never run *just* a rear bar, it will nearly always make the car quite handle poorly. The earlier, live axle/non-IRS cars usually don't need a rear bar at all, it usually makes them pretty unpredictable.)

As to the shocks themselves, I'd always replace the oil inside, as a matter of course, while they are off the car. Just drain out through the small filler hole (might take overnight), then clamp the shock upright in a vise and fill until the oil is level with the small filler hole on the side. Next, work the lever to get air bubbles out of the mechanism. It might take a dozen or two dozen full strokes, but eventually the shock should give smooth, steady resistance across it's entire stroke, both directions. If you feel any grittiness or roughness in the stroke, and are confident all the air is out (might let it sit overnight, then move another dozen strokes before judging), then it's pretty likely the shock needs to be rebuilt or replaced (www.applehydraulics.com is one source). I agree with Gary, it's a good idea to replace the links, too, but looks like you have already done some work there.

I don't know about grades of oil. AFAIK, "fork oil" varies a lot from manufacturer to manufacturer in terms of viscosity. They just aren't consistent with viscosity grading, the way engine or gear oil is. I have some "10 HVI semi light fork oil", whatever that means, out in my garage right now! Seems awfully light for these car's shocks, but I don't have any 20W (approx.) to compare. I do have some of Moss' Armstrong-specific shock oil. There's no viscostiy rating shown on the label, but I'd guess it's around 15 to 20W. It says it "contains special anti-foaming and anti-corrosion additives", which may or may not be in fork oil, I dunno. Still, the function is about the same, so I imagine fork oil formulas are pretty similar to shock oils.

You can experiment with tuning the shocks with different oils. I've even heard of putting STP in there, but that seems to me like a big chunk of overkill! Some use motor oil: racing type that has no detergents, which would cause foaming. Here 30, 40 and even 50W is sometimes used, or blends to get in between viscosities, but these can make the shocks pretty darned stiff!

I think the main fault of Armstrong lever shocks is that they are more inclined overheat under hard use and the oil will then lose it's viscosity, at least temporarily until the shock cools a bit. For serious competition, lever shocks were often replaced with larger models, I suspect mainly for the additional oil reserve capacity and better ability to shed heat. ISTR seeing some Armstrongs with an additional, remote oil reservoir, too, but can't swear to it.

There are also methods of changing the shocks' valves or parts of the valves to adjust dampening. (Do some Googling about it, if you want more info.) And, Cambridge Motorsport even makes a custom, fully adjustable valved shock, but it's pricey and might need different mounting brackets.

If you see *a little* oil on the shock body, near the lever shaft, don't worry about it. That's common and I've heard it explained that Armstrongs are actually designed to weep just a little oil out through that seal, to carry dust and dirt away from the innards of the shock. However, if there is quite a lot of oil on the shock body, the seal needs to be replaced (which is not a DIY job either).

Say, have you considered converting to a tube shock? Seems to me that everyone who does this on the IRS TRs really likes the improvement. (I wouldn't bother making this change on the earlier, non-IRS TRs with their multi-leaf springs, but might if using a special monoleaf spring instead.) There are more easily adjustable tube shocks, as well as gas-filled models to choose from. Just a though, if it's the sort of thing you are interested in doing with the car.

/ubbthreads/images/graemlins/cheers.gif

 

[Tinster]

Thanks to both:

Yes the front has sway bars that I replaced all the rubber pieces. I have Applehydraulics bookmarked as a source.

I saw the opening at the top of the shock but did not know if the oil inside was under pressure so I stayed away from it. Now I know I can open the plug and peer inside. I'll have one off this afternoon and report back.

Conversion to tube shocks? I think not is possible for me. I am a one man restoration team here on the island. That conversion is way above what I can accomplish in my home garage. I have a drill press and grinder and hand tools here at home. That's it. The portable welder guy charges a small fortune to come to your home.

The Western Auto folks are kind enough to rent me a mechanic and lift by the day (when my TR is running!) We bumble along with Bentley Blue Book but get things inworking condition.

I have many greater needs and priorities for use of the very expensive lift and mechanic. Replacing the worn out clutch at Western Auto will probably cost me over $2,000.(if nothing goes wrong)

 

[swift6]

[ QUOTE ]
Conversion to tube shocks? I think not is possible for me. I am a one man restoration team here on the island. That conversion is way above what I can accomplish in my home garage. I have a drill press and grinder and hand tools here at home. That's it.

I have many greater needs and priorities for use of the very expensive lift and mechanic. Replacing the worn out clutch at Western Auto will probably cost me over $2,000.(if nothing goes wrong)

[/ QUOTE ]

You can do a lot on these cars with a good set of hand tools. Thats part of the beauty of LBC's. Lists and Forums like this make it even easier to get the info you need and can help decipher parts that the Bentley glosses over. Many of us are also 'one man restoration teams'.

With the tube shock conversions. If you can take the lever arms off you can convert to tube shocks. The majority of the conversion kits are bolt on. None of them require special tools or welding.

Don't down play your abilities too much. Many of us started out eager to learn but low on knowledge. Were here to help. /ubbthreads/images/graemlins/grin.gif


/ubbthreads/images/graemlins/cheers.gif

 

[Tinster]

I am getting faster!

Alan, Thanks for the very detailed description: I got
the car jacked up, wheel off, 2nd jack under trailing to
compress the coil spring a bit and then a 3rd jack stand
set under frame (I'm paranoid of the car squashing me
while I'm under).

Then I removed the shock sustaining only one skinned
knuckle and a 1/2" long slice to my wrist! All in under
one hour time!!

The shock is an Armstrong (Aussie made)and my toothpick
dip stick found no oil below the top access hole. Lots of
oil leaked on the outside casing cylinders.

I removed the spring valve at the bottom and less than
25 cc of oil was then extracted. The spring valve spring
is dull copper color indicating a competition valve spring. It looks to be in v. good condition. The oil was very gooey
and the color of melted caramel.

I will let it drain over night as suggested. I found this excellent graphic and description for adjusting Armstrong
TR lever shocks. Well worth a look by all of us lever
shock non-experts.

https://mywebpages.comcast.net/rhodes/shock.html

By the way: What is the trick to removing the connecting
link assembly?? I replaced the bottom bushings but can't
get the arm itself off the shock. I banged it a bit with
a hammer but was afraid I might damage the threads.

Again, a large THANK YOU to everyone.

 

[Tinster]

Opps, I forgot.

Later this week I'll post a photo series on my experience
of how to remover and refurbish TR6 lever shocks. I may as well share my cuts, scrapes and home grown diagnostics for
the other poor souls like me who understand virtually
nothing about auto mechanic repairs.

 

[Geo Hahn]

[ QUOTE ]
The Western Auto folks are kind enough to rent me a mechanic and lift by the day... I have many greater needs and priorities for use of the very expensive lift and mechanic. Replacing the worn out clutch at Western Auto will probably cost me over $2,000.

[/ QUOTE ]

FWIW -- You do not need a lift to replace the clutch, indeed a lift would be of no use. The front only needs to be raised a couple of inches -- all the real work is done in the cockpit (after the interior has been cleared away).

 

[Keoke]

HI Tinster, for $2000.00 I would learn to replace a $200.00 clutch it isn't rocket science by any means. The Shocks you mentioned leaking are shot and need a rebuild. Send them to Jeff at World Wide auto here in the US.---Fwiw--Keoke

 

[vettedog72]

First, glad the storm just gave you rain. The lever shock has a filler bung and it can be access with out a great deal of goings on if you get it on a lift or jack stands. The problems I have seen are leaks out of the main arbor. If it just leaks a little, just refill it and enjoy driving. Other wise, the tube shock conversion can be done with out welding, boring, etc. I got my conversion from a user on this news group. It works very well and I don't have a clue if it would stand up to road racing. On the regular road it is a great improvement over the left lever shock being dry. Personally, if Triumph had thought of it, I believe they would have used the tube over the lever; it looks much less expensive to construct and shocks can be replaced much easer and less expensively then the lever shock.

 

[Tinster]

An update from Google research.

It seems the lever shocks on our TRs were designed
on purpose to leak oil as a flushing action to remove
road dust and grit from the lever arm/housing joint.

They were always intended to have oil added as a routine
maintenance item.

Today I go in search of a Harley dealer to purchase the fork oil to refill the drained Armstrong.

tinster in PR with yet another tropical gully washer upon us!

 

[Tinster]

Thanks all:

The first shock came apart easily, was cleaned and
refurbished by following all advice. The arm now
provides a quite strong, constant resistance through
the entire range of motion. No gritty or jerking motion.
Smooth.

Next weekend- the other one!!

 

[Alan_Myers]

Hi Tinster,

Yes, there is always a bit of seepage out of the seal around the shaft. You'll have to use your own judgement about when it becomes "too much" and new seals are needed.

Since you have pulled out the dampening valves, you can see that there are some opportunities there to experiment with tuning them, if you wish. Somewhere on the Internet I recall seeing a writeup on the subject of shimming a little here and there, using different rates of springs and changing out the valves for other sizes, to change the shock characteristics. One common "race trick" was to use the valves from the front lever shocks on MGB to stiffen up the rear shocks on TRs.

Note that there are actually different lever shocks used on various models of Triumphs, although the dampening principle is the same with all of them. The ones on my TR4 are perfectly vertically mounted and have the filler hole partways down on the side. That also serves as as an overflow, to measure the amount of oil in the shock and prevent overfilling.

With the top filler hole, some caution to not overfill is necessary. There needs to be some air space left in the shock to allow for expansion as it heats up in use.

If totally topped up, I think you could expect the shaft seals to blow out in pretty short order and some serious leakage to be the result!

Perhaps one of the service manuals has exact specs just how much oil quantity needs to be in those top-fill shocks. I don't know, haven't needed to look because of the design of the particular shocks on my car.

The shock links also vary a bit from car to car.

Thanks for adding the photos and info in your other thread. I'm sure folks will find it useful.

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