TR6 '74 TR6 Rear Shocks

[Rocketpig]

I have a '74 TR6 and need a seal kit for the original rear box shocks.

Does anyone make these? I'm not sure where to check. I know companies like British Victoria offer refurbed shocks, but does anyone make just a rebuild kit?

 

[sammyb]

I have never seen a rebuild kit. I would just search on ebay for a set, or buy from the Roadster Factory, because I think they are on sale right now.

 

[Dave Russell]

To my knowledge, there are not any seal kits available. When a shock starts to leak it is usually caused by wear in the shaft bores or the shaft itself. Not a simple replacement job. See this reference for more info. Also, in my mind, this is the only place to get a 100% successful rebuild. When I asked Peter about what kind of fluid to add if needed, he replied, none needed. If a shock ever leaks send it back for a free replacement.
https://hometown.aol.com/bgahc/myhomepage/index.html
D

 

[Rocketpig]

Thanks for the help, guys. For around $55 a side, I see no reason to fight with attempting to rebuild them myself.

I have enough to do to the rest of the car. It's completely stripped right now (except for bodywork). /ubbthreads/images/graemlins/frown.gif

 

[Alan_Myers]

Hi,

I agree, you are better off replacing those old shocks, if they are leaking excessively. You'll need to send in your old ones as cores. Or, you might just try putting in new oil and bench test the shocks to see if they are okay, before replacing.

I estimate the lever shocks on my car are at least 30 years old and they are still in perfect working order. I just replaced the oil in them. Meanwhile, a set of expensive Koni shocks on the front of the car for a lot less years, probably 10 yrs actually on the road, were worn out and needed rebuilding or replacement (I installed new Konis, but will have the old ones rebuilt as spares. The new ones are slightly different.)

Personally, I think lever shocks work well and have never bought into the need to change them out for "modern" shocks, along with all the re-engineering needed to fit those to our old cars.

The original rear lever shock used was an Armstrong DAS9, I think, on all the "big" TR series. A race oriented upgrade is the larger DAS10, but that shock requires a larger mounting bracket be welded onto the frame.

Another good source of lever shocks not yet mentioned is Apple Hydraulics, which also offers uprated versions if you want a heavier duty shock but still the standard DAS9 size. www.applehydraulics.com is their website.

If you wish, it's also possible to simply replace the oil with heavier, for increased dampening. Try a motorcycle shop for 20W or 30W fork/shock oil (stock is approx. 10-15W, which Moss and TRF sell). I've heard of people using 40W and even 50W racing motor oil (non-detergent) in shocks, but that seems pretty extreme to me.

Changing oil is easy. Just be a little careful removing the large nut on the front/bottom of the shock, it has spring loaded components of the valve mechanism behind it that must be reinstalled in the right sequence. The filler hole is a smaller nut at the top/rear of each shock. Shocks are most easily refilled when off the car, in a vise or something to hold them upright. It's important to repeatedly actuate the lever while refilling, to work out any air trapped in the valve area of the shock. You'll also notice any grinding or failure of the mechanism, while doing this. (The movement should have steady, smooth resistance both up and down.)

Another option is a set of adjustable lever shocks, a modification offered only (to my knowledge) by Cambridge Motorsports in England. Pretty neat setup. www.cambridgemotorsport.com is their website.

Or, it's possible to fine tune shocks using different valving setups. I've heard of using valves from MGB front shocks in the rear Armstrongs on TRs, for about a 25% increase in dampening. I haven't tried this.

One suggestion that might make your life easier. Replace the bolts holding the shocks to the bracket with 3/8" NF socket-headed bolts. It's a whole lot easier to get a hex/Allen wrench into that narrow space, to tighten and loosen the bolts. Use a nylock nut on the back side of the bracket. I recently made this change and it makes the shocks so much easier to remove. Just be sure the shank of the bolt, the unthreaded area, is long enough to keep threads out of the hole in the shock and the bracket. All the knocking about that shocks get, threads inside there will grind the oversize holes mentioned in the article referenced earlier. You might need to add a washer or two to fine-tune the fit of any bolts you find.

Cheers!

Alan

 

[Rocketpig]

Information.... Overload...

*head explodes*

Heh, thanks for all the info... I haven't driven this car yet (tore it down immediately upon purchase)... Do you guys think that heavy-duty shocks are the way to go?

 

[Alan_Myers]

Hi again,

You might or might not want heavy duty shocks.

IRS Triumphs "squat" under acceleration off the line. Some more than others. The TR6 tends to be pretty softly sprung, I suppose a concession to give it a nicer ride for greater appeal in the American marketplace. But, that leads to more squat and, overall, less precise handling.

As a result, it's not uncommon to find heavier springs installed by a previous owner in an effort to improve handling and reduce the squat. If heavier springs are installed, you might want to think about installing heavier duty shocks.

However, keep in mind that you can change the oil weight and/or valving in the standard shocks to increase dampening, with good results, should you put a set on and find they don't do as well as you'd like.

So if you don't know what springs you've got, I think I'd recommend sticking with standard-rated shocks. If you know you have some uprated springs, you might want to consider heavier duty shocks. It's not easy to guess, and might be best to stick with standard rated until you get the car back on the road, evaluate it more thoroughly, and then decide if some changes are needed.

Cheers!

Alan

 

[Rocketpig]

Great. Thanks for the help. I'll just go with standard for the time being.

 

[jsneddon]

brilliant idea on replacing those bolts with an allen head type.... Now I just have to figure out how to get the dang things off. I read somewhere that the 1/4 in drive craftsman socket will barely fit in there. Last time I tried tightening them up I gave up because I couldn't get a socket onto the bolt head. I'll be trying the 1/4 inch drive socket in a couple of weeks and hopefully that will do the trick. But once they are off I'm definatley going for the hex heads!

 

[Guest]

I had a problem with my TR6 bottoming out on a really bad bump. I opted for the competition springs for the rear from BritPartsNorthwest. They were the most knowledgeable in this area for me. Lowered the car about 1 inch, no noticeable harshening of the ride, zero bottom-out. I used their one-piece tube shock conversion (Spax) (they claim they are the ones that actually manufacture these conversion brackets) and am satisfied with the whole setup. I had tried springs from TRF and they were way too long, with very little advice to correct the problem except to return them. BritParts is very knowedgeable.

Bill

 

[Guest]

I've got the "fast road springs" from Moss on my car now, stock ride height. I went with the heavy duty rebuilt rear shocks from Apple that Alan mentions above. I'm very satisfied with this setup, really tightened the rear end up a bit. It's a little stiff over rough roads but not to the point of being overly harsh. I was very impressed with the job apple does on these, they look like new units. I had them do the throttle shafts and butterflys in my carb bases as well, they did an excellent job.

I originally thought of going with tube shock conversions so that I could eventually fit a nice set Konis, but I read that some people had cracks develop in their frames from the tube shock mounts, stuff like that. I've never actually seen anything like that but it sort of scared me off of the tube shocks for awhile. I'm sure there's a lot of people around here using them, maybe they can give their experience, I'd like to hear how the tube shocks work out.

 

[trboost]

Hi all,
I have also heard of the "feared" cracked shock mount when converting to one pc tube shocks but have never seen any actual failure or damage caused by this change. I can only asume if this change caused the original mounting point to fail it was in very poor condition to begin with. This welded mount is exposed to all the elements & must be structually sound. The reason for the change is to provide better damping & it is this more accurate damping that will put pressure on the mount. Another possible reason is a loosening of the mount bolts, if they are not torqued down properly it will allow the bracket to snap up & down exerting undo force on the mounts.
I converted to the one pc bracket two or three years ago & have found only positives on the change. First off, the old lever arm design is just that, OLD & outdated. The leverage design is slow to react & is connected with a link that is truly the "weakest link". I have found that the ride is far superior, rebound & wheel control is much improved & the car seems to have a more stable ride. My kit came with KYB gas shocks but I would probably caution using Koni's or Spax on very stiff setings unless the mounts were reinforced.
If originality is a concern I absolutly understand, but you can not discount this conversion on the basis there is nothing to gain & damage will occur.

 

[Alan_Myers]

Hi Jim,

Been there, done that! Old bolts can be a bugger to get off or tighten.

Try this: First soak the nuts on the inside well with WD-40 or any sort of penetrating oil. Let it sit for a day or two or three, depending upon the condition of the nuts and bolts.

Then, use a large bladed, straight screwdriver and, from the outside, sort of wedge it between one of the flats on the bolt head and the body of the shock, where there is very little clearance.

Unless everything is severely rusted, this can often be all that's needed to hold the bolt while the nuts are loosened from the inside.

Frequently, those nuts and bolts are a bit loose anyway, which is what leads to reaming out the bolt holes in the shocks and brackets. Careful selection of a replacement bolt can insure the shank of the bolt is long enough to prevent any threads inside the hole in the shock or the bracket, preventing the reaming effect.

This loosening method can be reversed, to tighten the nuts & bolts if original style hex headed bolts are used. But, I personally just prefer to replace the bolts with socket-headed as a better and more permanent solution, even if it's non-original.

If the nuts and/or bolts are heavily rusted, a nut splitter or just carefully cutting the bolts away on the inside, say with a hacksaw blade, might be the only options. I wouldn't recommend using a welding or propane torch in there, since the fuel and brake lines are right there and the gas tank is directly above.

Alan

 

[Alan_Myers]

Hi,

Earlier I posted that I saw little reason to swap out the old lever shocks for telescoping, because I think the levers are quite capable. I still think this is true for most drivers, who aren't using their cars particularly hard.

However, I agree with what you are saying here, that "modern" shocks bring some advantages and solve some problems, so long as they are well-installed. One key consideration is that in the U.S. lever shocks are somewhat "alien" and there is little interchangeability., information or resources. Meanwhile tube shocks are the norm and there are many choices available.

But, the old levers can be improved and tuned just by changing the oil or valving. The connecting links are a problem area, with rubber in two places that allow too much compression or free play before the dampening effect of the shock takes over. These links are often overlooked and should probably be replaced more often than is usually done, to get good performance out of the shock. And, it's possible to change to a more rigid type of link. Revington TR and perhaps some of the other TR vendors in England offer this easily-installed improvement. These links will likely make for a little more road noise, a bit of a trade off for improved shock effectiveness.

I also need to qualify my statements by adding that I more often find myself working on the earlier, leaf spring/solid axle suspensions, which see less benefit from a switch to a modern telescoping shock. TR4A IRS and all the later IRS cars certainly see more benefit from making this modification.

On any of the cars, it seems to me that a rear shock conversion that includes brackets welded to the frame rails, rather than an upper shock mount on the body sheet metal in the wheel, would be much preferred.

Just my 2 cents worth.

Alan

 

[CSM3]

Ditto what TR6Bill said about the TRF springs. I replaced mine two weekends ago, and what was a high-sitting rear with the old springs now looks like a raised-rear hot rod. To compound the problem, the KYB shocks in my conversion kit give very little, transferring the jolts of our lovely streets to the driver and flexing the frame. The apparant over-stiffness of the KYBs was brought to my attention by a local mechanic whom I trust. If I can't find something softer (suggestions, please), I may return to levers.

 

[Guest]

Stuart,
As noted in an above post, see that I called Brit Parts Northwest for my competition springs and used their tube shock conversion. However, the KYB shocks that come with this conversion are way too stiff for my liking. Then changed them for Spax adjustable and got plenty of damping without the harshness by dialing it in. The springs did indeed lower the car about 1" but amazingly did not change the geometry of the rear alignment. Had it checked. So now, I have a better ride height, good damping, no bottoming. TRF just couldn't understand that their springs would jack the car up like they did. Whatever. Too, I stayed with rubber bushes for the springs to preclude any additional harshness in the ride.

Where in Louisiana are you? I am in Franklin, in the banana republic of South Louisiana.


Bill

 

[trboost]

Hi Bill,
I'm surprised you found the KYB's to stiff. I always considered them soft compared to adj Koni's even on the lightest setting. I have Koni's in the front & left them at the factory setting & still find them stiffer than my rear KY's. I think the decieving part is the gas design that forces the piston to extend makes it seem stiffer to the installer but I think it has a more streetable valving compared to spax or Koni.
TRF sells stock "road" spring, Handling springs & competition springs. Its the competition springs that have a 20% higher spring rate & lower the car approx an inch. The final height can be tweaked with aluminum spacers if desired. I have had these springs for 4 years & they are terrific. I believe TRF re-sells the Goodpart compettion springs under their name. The proper TRF # is HP132.
Springs sold as "uprated" usually raise the ride height & in my opinion detract from the look & adversly affects handling.

 

[Simon TR4a]

Agree with both Alan Myers and Mitch, my experience has been with irs cars (TR6 and TR4a), I like a fast road spring to resist squat, and feel to control a stiffer spring you need an uprated shock. I have used lever shocks, KYB that came with the kit and Spax adjustable, and find I like the Spax for fast driving, the KYB I find too soft with my springs (fron Triumphtune (Moss), rated at 390lbs/inch compared with 290 for stock.)
My springs lowered the car only 1/2 inch to 3/4 inch, not really noticeable, measured from garage floot to lip of wheel arch.

Other factors can confuse you when evaluating the effects of changes; I felt the back of my car was bouncing out on less than smooth corners, but I realised later it was too high a tire pressure not the shock change I blamed it on.
Embarrassing but true, make sure its a fair comparison.
Simon.

 

[Alan_Myers]

Hi all,

Regarding TRF springs for the IRS TRs, they note in their catalog that these increase ride height of the car slightly (this is illustrated with Charles' own TR5) and strongly recommend they be installed in a set of four so the car sits level. I suspect these are "rally" springs from one of the British suppliers, but have no confirmation of that.

Alan