Anybody ever rebuild a lever arm shock?

[vping]

Just curious to know what it takes to rebuild any of the lever arm shocks that are on our cars.

 

[jlaird]

All it takes is Peter C and a couple of days.

 

[Steve_S]

It isn't worth it. Most who have tried have either damaged the shock or have not been able to get the required rebuild parts. I'm currently rebuilding suspension, steering rack, kingpins, etc, but I'm not touching the shocks. They're going to Peter.

 

[aeronca65t]

I took one apart a few years ago just out of curiousity (it was crash-damaged anyway). I have access to a machine tool lab with big arbor press, etc.

I think it would be a huge pain to rebuild one of these without a professional setup and the experience.

Looks like something better left to someone who does this on a regular basis. As you have seen above, Peter C. has an excellent reputation for this.

 

[ddrumman]

Who is Peter C, and how can we get in touch with him?

 

[Steve_S]

https://www.nosimport.com

 

[David_DuBois]

I successfully rebuilt the front shocks on our TD, but it was a miserable job with a number of false starts and several retries before I finally got them to stop leaking. 25 years later, when they again failed, I didn't hesitate a moment before sending them to Peter Caldwell - money well spent!
Cheers,

 

[Steve_S]

Did I mention the lifetime warranty against leaks? The shocks I'm sending him aren't even leaking. I just don't want to ever have to take them off again.

 

[PAUL161]

Vinny, do yourself a favor and send them out. Working properly, they are an excellent shock. But, unless you just want an education and have some free time, don't fool with them, it's not worth the aggravation. JMHO. PJ

 

[vping]

I took one apart a few years ago just out of curiousity (it was crash-damaged anyway). I have access to a machine tool lab with big arbor press, etc.

I think it would be a huge pain to rebuild one of these without a professional setup and the experience.

Looks like something better left to someone who does this on a regular basis. As you have seen above, Peter C. has an excellent reputation for this.

Out of curiosity and wanting to do all things myself is why I posted about it. If many many have tried and I need to spend a lot gearing up to do it, I'm leaning toward Peter C. I have several I can take apart to experiment but and am still curious but will go to him. I contacated him about 2 months ago but never got around to it. He on the list of contacts again for what I need to get done.

 

[jlaird]

Just for info, Peter even likes old cores that are laying around. He does rebuild them and sell them to others with problems. Also uses them as exchange units.

Call and talk to him if you have some, he likes phone calls and just may make you a bit of a deal.

In addition, lets keep the old cores in circulation. The supply is not infinate.

 

[vping]

That was my plan as I know I have:

2 sets front & rear Armstrong for a TD - 1 Installed on car 1 spare set.
1 set front & rear Girling for a TD - Soon to be sold or ebayed.
3 sets front & rear MG Midget
6 sets frotn & rear MGB - 3 sets on Cars

Been purging lately and if I can trade for labor I certainly will. That is if they are cores. Most of them still have great pressure/resistance and are not leaking.

 

[jlaird]

After so many years even if not leaking I would expect them to be cores. Just because they do not leak does not mean they are working as they should.

 

[PeterC]

Just curious to know what it takes to rebuild any of the lever arm shocks that are on our cars.

I have a few minutes and can explain what's inside.
The usual failure is that the shock leaks at the shaft. If the shock loses enough oil from here, then problems occur inside with the pistons, etc. The ride becomes noticeable softer at this point. So the first thing to do is seal the shaft. The original "seal" is actually a 1/2" wide rubber packing retained in the shock by a steel washer that's crimped in the body. (the pic is of a Spridget front apart) Note that when the seal has leaked, that grit is likely to be attracted and score the shaft, so replacing the seal with the same kind wont last, and removing the old one will have damaged the retaining slot.

Regrettably, there are no oil seals made that are the correct size for the bore and shaft combination. There is one slightly smaller OD that some "rebuilders" mud in with silicone. The shaft will often be pitted and scored so that the seal will quickly wear, however. If the shock had been low on oil long enough, the surface that the shaft rotates in in the body will also have worn making a seal problematic. There is no bearing in the zinc body, originally.

Taking a front B apart is straight forward, push the shaft out. Taking a rear or other single arm apart is a little harder, as you should pull the arm and shaft together. (Drilling and pushing from the core plug side creates more problems) This requires some fixtures and hydraulics.

Once the shock is apart, you can give it a thorough cleaning and inspect for loose wristpins, and damaged poppet valves on the pistons. The main valve is the least problem, and usually just needs cleaning. Sometimes the piston bore will be scored from a loose wristpin, and needs to be sleeved.

I wont describe here what we do, but we overcome and address all of these issues, and more.

What you can try, and it's what I did on my first shock in 1972, is cram some rubber washers (garden hose style) in the bore and add a steel washer against the arm to hold them. Or what another "rebuilder" does is cram what looks like a thick tube-shock type mounting bushing in the hole. So long as the shaft isn't pitted, and the bearing surface is good, you may be able to successfully seal the shock. It's not what one might call a rebuild, but it might serve you for a while (and people do pay money for it).

Maybe I should do a proper write up for the Wiki?

Thanks for listening.
Peter C.

 

[jlaird]

Or you could come to the Lake next summer where I understand Peter is going to give a tech session on shocks.

I bet he even has some cutaways.

 

[vping]

Thanks for that description. I was assuming that parts alone might be difficult to source unless you really know what you are doing. I spoke with you (Peter C) via email a few months back and should have taken you up on the offer. Finances are not what they are yet but I will be trying to get to it very soon. What's the TAT on a TD Armstrong Front or rear rebuild these days?

 

[jlaird]

Priceing is on his web page for each kind of shock.

 

[joeycessna]

I successfully rebuilt the front shocks on our TD, but it was a miserable job with a number of false starts and several retries before I finally got them to stop leaking. 25 years later, when they again failed, I didn't hesitate a moment before sending them to Peter Caldwell - money well spent!
Cheers,

Hi, I wonder would any of the "stop leaks" products work to revive the seals? However, it's probably pitting on the shafts that could also be a problem.

 

[JPSmit]

Hi, I wonder would any of the "stop leaks" products work to revive the seals? However, it's probably pitting on the shafts that could also be a problem.

This is one of those times that just doing it right makes the most sense. It isn't expensive, it lasts and it transforms the ride of the car. It is also worth making sure things like suspension and brakes are kept in good and safe condition. I wouldn't and I am the king of cheap and the baron of bodge.

 

[Russ V]

I tried to rebuild my front shocks and it was a disaster. Never worked right again. DEFINITELY worth sending to Peter C. Remember..... shocks can be a safety issue and never worth gambling with safety.