Shock tube replacement

[mbell]

Hi,

My big job while the cars off the road for the summer is a suspension refresh. I am leaning heavily towards TTR spring/shocks. These are height adjustable at the front and so makes sense to make the rear adjustable too.

I think the two basic options for that are:
- Fit new adjustable shock tubes
- Remove the original spring perches and weld on adjustable ones

I generally like to be able to reverse any mods I do, so kind of leaning to fitting new shock tubes and this also avoids the risk of damage/issues from my limited welding skills. However I am less convinced about the practicality of changing the tubes. I don't want to fully strip the hub carriers down to be able to heat the entire units, due to lack of a press and general effort/time. So concerned about the removal/fitment of new tubes.

So interested to hear people experience in removing/fitting shock tubes?

I do have electric heat gun and plumber's propane torch so can do limited local heating. I should also be able to get away with putting the new tubes in the freezer before fitting.

Thanks,

Mark

[Certified Lotus]

It’s unlikely you will get the shock tubes out of the bearing hubs unless you completely heat them in an oven or outdoor gas grille. If you use a torch every time you move the tip your changing the temp of the location and the entire casting will be at uneven temps.

Best to “bite the bullet” and remove the bearings (yes you need a press), put the entire hub with shock tube in a gas grille at 400 degrees for 20 minutes, take very hot (use welding gloves and pliers) hub and quickly but gently put in a vice. Use soft hammer to knock out the tube from the bottom up. Take frozen new shock tube and slide in. (You should have shock tubes left in freezer over night).

You only have about 1 to 2 minutes to get off the grille, remove and reinstall but temp drops too much and you have to start all over again. Have everything ready to go and do a dry run before actually doing it.

While your at it, replace the bearings!

I just did this for Ross Robbins Elan while he was on his road trip. I had him and Ray at RD Enterprises watch the whole process in detail as neither had ever done this before.

[mbell]

Thanks Glen, not what I was hoping to hear but that is life. I was hoping I might be able to rig something together and press them out with a bit of light heat but sounds like that likely to result in failure.

I don't have grill big enough for the whole unit with tube or press for doing the bearings. So sounding like I am not equipped for such a job. Buying a press probably is sensible enough but I am missing a spot in the garage for one, so been trying to avoid buying one. Doubt a buying a big grill and then using for car parts will fly with the wife either!

I do have a friend with an industrial oven and a press a few hundred miles away, which is likely better route to look at if i want to change the tubes.

Thanks again.

[gjz30075]

I do have a friend with an industrial oven and a press a few hundred miles away, which is likely better route to look at if i want to change the tubes.

Thanks again.

It is a lot easier with another person.

[mbell]

It is a lot easier with another person.

I can believe that Greg!

Thinking I'll get the tubes, maybe have a go to see if I can separate them themself. If not take them for a trip.

[Bud English]

I've only done one tube R&R and it was before internet. So I was winging it.

I used a propane torch successfully. Keep it moving throughout both the removal and install. There's a lot going on all at once and having a second person really helps even if all they do is man the torch.

Ditto on all the recommended prep work prior to attempting this. Remove the innards!

Be sure to mark a reference point on the housing to point the brake line bracket, if your new tubes have one, in the right direction.

Also make sure the exposed part of the old tube at the bottom is totally clean with no dirt, rust nor paint. It's going to be driven out through both sides of the housing and you want to score the mating surface as little as possible.

With the torch being used for heating you almost have to separate the removal and reinstall steps as the carrier will cool down too much. I went with dry ice in and around the new tube rather than the overnight in the freezer method. It got colder and I would think a little skinnier.

The scariest parts were pointing the torch at the housing for the first time and starting the new tube into the housing. Make sure it goes in perfectly straight and corrected oriented at the start. It's not a drop in fit, but needs very little persuasion to tap it into place. Once through the top side, mine was cleanly lined up with the bottom hole. Once you start, don't stop.

...and good luck!

[gjz30075]

Once you start, don't stop.

Key statement right there.

[mbell]

To update this thread. At the weekend I visited a friend with industrial oven, turns out it for heat treating metal. He also needed to replace shock tube on his recent Elan purchase. The heat to 400/500 and knock the tubes out didn't work and we had to give up and revisit.

In the end we both used propane torch and pressed them out. My friend was able to use a hydraulic press, once he made up some pieces to hold the strut tube correctly. I used a bearing separator/puller* rig to push the tube out, I used a 36mm socket and 1 1/2" pipe hanger bracket as mandrels.

I am yet to re-insert the new tubes but plan to attempt the grill/Freezer/hammer method for insertion. Will have to see if it works...

* https://www.harborfreight.com/bearing-s ... 62593.html