Front Shock bolts

[DerekJ]

I noticed a strange noise from the left hand front wheel on bumpy road sections, I guess this crept up on me gradually.

On checking I quickly spotted loose shock bolts. One was particularly loose the others just a turn or two.

When I tightened them the loose one wouldnt tighten properly indicating problems with the thread. I tried a new bolt but had the same problem

I guess that means the thread in the shock mount needs re=tapping.

Never having re-tapped anything before do I just use the same size tap as the current thread? (and what size is it?) /ubbthreads/images/graemlins/confused.gif Or does that not work. Do you have to go bigger? Will I have to disassemble everything or could it be done in place?

BTW I unfortunately had to cancel my trip to Goodwood this weekend and then found out the day after that Stirling Moss will be racing in a 100S - not fair! /ubbthreads/images/graemlins/mad.gif

thanks in advance

 

[John Loftus]

Derek,

The problem with drilling and tapping for a larger size is that you will then need to use a larger bolt and increase the hole size on the shock which will weaken the shock. I had a few stripped threads that I fixed by using a Heli-coil type thread repair. For the 3/8-24 Heli-coil, you drill out the damaged threads with a 25/64 drill (after removing the shock). Because there is not much room between the shock plate and the wheel housing it was necessary to use a low profile right angle attachment to the drill (I think I also used a short drill bit). Then you make new threads with the tap that comes with the kit (3/8-24). There is a tool with the kit that you use to screw the heli-coil into the new tapped hole until the coil is a 1/4 to 1/2 turn below the surface of the hole. Then you remove the installation tang on the coil by bending it back and forth or use a punch to break it off. Once installed you can use a 3/8-24 bolt to reinstall the shock. This worked fine for me but some will say the best fix is to install a threaded plate in the space where the shock nuts currently reside or replace with a new shock plate top.

Cheers,
John

 

[Dave Russell]

Hi Derek,
Once you get the threads repaired, I have some suggestions.

The front AND rear shock mounts as they come, are really marginal in the first place. The shocks are made of soft aluminum & other than a tight fit between the mounting holes & the bolts, there's nothing else to take the high forces involved in the shock trying to move laterally on it's bolts.

I use grade eight socket head bolts. More room to get the wrench on the bolt heads. Use HARDENED washers under the bolt lock washers to prevent them sinking into the soft aluminum. Only a thousandth or two of "sink" will remove all of the bolt tension.

If the shock holes are not a tight fit on the bolt shanks, for lateral location, have the correct diameter of steel sleeves/bushings installed in the shock mount holes. The rebuilt shocks that I got from World Wide already had steel bushings installed. Don't know if this is always the case.

Use star washers under the bolt heads. Good star washers will hold tension better than split washers. Loctite doesn't hold tension, it only prevents unscrewing & would have to be renewed each time the bolts were re-tightened.

Tighten the bolts to 35 ft/lb & CHECK THEM FREQUENTLY. If your shocks are set up with heavier than normal damping or fluid the problem is made worse.

A Heli-coil may work. There may be more than one bad thread. A better fix is to cut the end of the shock tower open, remove the nuts, & replace with a high quality threaded plate. Close up the cuts & ready to go. I sincerely hope that you don't have to go this far.
D

 

[John Loftus]

[ QUOTE ]
Use HARDENED washers under the bolt lock washers to prevent them sinking into the soft aluminum.

[/ QUOTE ]

Dave, I tried this but the hardened washers still sink into the aluminum over time. I wonder if the steel sleeves that you have helps to share the compression from the bolt .. keeping the soft aluminum from taking the full compressive force? Is so, another good reason to add sleeves.

I did not find elongation on any of the front shock mounting holes but the original rear shocks had quite a bit. I replaced the shocks but have heard of some owners adding additional bracketry to interlock the shock body to the chassis bracket to keep the shock from shifting up and down if/when the bolts work loose. Too bad the factory didn't think of doing this.

Cheers,
John

 

[Keoke]

HI Derek, all the usual solutions have been covered.However, there are steel inserts EZ LOCK is one source that can be put into the esisting bad nut to restore the original size thread.Alternatively, for a single bad bolt , I might suggest that you simply drill it and tap it for the next size bolt the bolts are too small anyway. Contrastingly, In this application I do not suggest using the Heli Coil, You can always go the whole nine yards later---Fwiw---Keoke

 

[Dave Russell]

Hi John,
I suspect that the sleeves were primarily used to salvage otherwise unusable front shock bodies. But -- Perhaps, the greatest benefit would be as you describe. The sleeves certainly keep the washers from chewing into the aluminum & they are definitely a press fit in the shock bodies. I still periodically check bolt torque, but they haven't loosened.

I have considered more positive location on the rear shocks, as you say. Being a bit lazy, I just haven't done it, so I just keep checking them. I had to make a thin wall socket to get solidly onto the hex head bolts. The socket head bolts DO make it quite a bit easier to check the bolts, so I still check the them frequently, especially with the heavier rebound valving that I had installed in them when Peter C. built them. Had to turn down the OD on some hardened washers to get them into the available space. So far, they have never been loose.

Come to think of it, the rear shocks had steel inserts also. Maybe Peter was getting short on undamaged shock cores? He certainly complained when I told him I wanted the shocks outright, no core returns. I don't think he would sleeve them as a matter of course. In any even't it appears to really help, maybe unintended consequences?
D

 

[John Loftus]

[ QUOTE ]
I might suggest that you simply drill it and tap it for the next size bolt the bolts are too small anyway.

[/ QUOTE ]

This wouldn't work for my front shocks. The original sized bolts are nearly a net fit through the holes so you would have to drill out the shock body to go to a larger bolt. /ubbthreads/images/graemlins/nonod.gif

Cheers,
John

 

[John Loftus]

Hi Dave,

Thanks for the additional info. The sleeves sound like a good way to go.

Cheers,
John

 

[shorn]

I found it impossible to get a socket on one of the hex bolts for my rear shocks. Can't remember if it was the forward of back bolt. Trying to tighten the nut using an open end wrench on the bolt wasn't very productive either. I ended up purchasing bolts that could be held with an allen wrench. I also put lock nuts on the bolts. So far they have stayed tight.

 

[bob hughes]

Derek
Can't answer your shocker problem, but Sir Stirling did not get into the 100S, the ride was given to Johnny Herbert instead who aquited himself admirably whilst in the presence of such eminant machines such as the C and D type Jags, Astons and that foreign rubbish from Italy, the Ferraris. He started around 20th on grid to finish around 6 or 7th, if the race had been longer I am sure he would have bettered that. You missed a great day.
/ubbthreads/images/graemlins/cheers.gif /ubbthreads/images/graemlins/england.gif

 

[anthony7777]

bob,yes great race,what place did the 'rubbish from italy'finsh? /ubbthreads/images/graemlins/cheers.gif

 

[anthony7777]

derek,i understand your problem very well,look i just took apart the entire front end of a healey,if your sure you will ever remove and replace the upper surface of your shock tower to cure the problem,ill cut these plates of the front end i have and you can get them welded in place when your ready,im not certain youll ever run in to these parts again but let me know soon!ill have to do something with them soon i.e..clean my garage etc.i dont think it matters what side you need ,i have and can send both if you like,as all things i "give away"i only ask that you reimburse me the postage,ill cut them out,clean, package,and ship them to you.i hope this can help cure your problem.

 

[vette]

Hello derek, I read your post the other day but haven't had time to get back to you on it. It so happens that I wrote an article on this condition about 2 years ago and it subsequently was published in the "Austin Healey Magazine" of the Austin Healey Club of America. It was finally put in the Mag. in the April/May 2004 edition, pg.- 17. As it turned out there was another article of almost exactly the same material as mine which turned up very shortly after I had presented my proceedure, of all places, right here on the BritishcarForm. It should be in the archives and would be about 2or3 years old. The editors of Austin Healey Magazine had published both versions of the article in the same edition, I'm sure to try to not offend anyone. The proceedure has been hinted to here. but this is how it goes. Also it has with stood many miles in the last three summers. this is what I did. 'I cut the outside vertical wall of the inverted metal stamping which the shock sits on with a cut-off wheel. I made a very fine cut and saved the piece that I cut out to weld back in place later. this allowed access to the void below the shock mounting surface where the nuts were tack welded to the underside. In my case I believe 3 of the 4 nuts were broken free. I chiseled the last on off to make the space clear of obstruction. The void area is about 6" by 3 1/2". I bought 5/16" steel plate and cut it to fit in the slot snuggly. I slid it into place from the outside edge fully seated back under the shock mounting surface. Now the new holes must be exact, as this is a main locating point for the front end alignment. I set the shock in place on the top of its mounting plate and was able to get it in the exact position which it had been in because there were minute impressions of its perimeter in the original mounting surface. THEN I USED A SELF-CENTERING PUNCH, to make a punch mark in the 5/16th inch plate. A self centering punch is one which has a rather shallow taper from its true outside diameter to its point. this type of punch will (using the exact diameter as the original hole in the shock) stand by itself upright in the hole thereby allowing the point to locate dead center in the hole. Made my marks, pulled the 5/16 " steel plate out of the slot. Drilled and tapped the plate the size of the original holes and threads. Reincerted the plate into the void below the shock plateform, put the shock in place, put in the bolts (new ones of coarse) and drew evrything up tight. Now I welded the outside edge of the 5/16" plate to the spring tower and the origninal shock mounting surface. Then I took the small piece of metal that I originally cut from the outside vertical edge of the frame, refitted it and welded it back from whence it had come. Ground the welds smooth and painted the frame in that area. Can barely tell that the proceedure was done. All four holes have brand new threads in 5/16" steel, and the plate being welded into place means that when you remove or change your shocks next time the plate will not move inside the frame. The proceedure has work very well and is not noticeable, except to an expert who might be quite familiar with a Healey frame. By the way, you can buy the replacement shock mounting stamping from many sources, ex: my most recent Moss catalogue, on pg 106, #40. BUT I'M NOT SURE IT CAN BE FULLING WELDED INTO PLACE without major tear down of the front end of the car. My proceedure only requires to remove the shock and separate it from the swivel pin. Good Luck,
Dave C.

 

[DerekJ]

Thanks Dave (and all others)

I guess its what I expected - no easy cure. I dont have the facilities to do this stuff in central Paris so Im going to have to find a reputable shop. Theres a guy who runs a Classic Car garage about 20 miles away and who races a Healey. I'll go and see what he thinks he might be able to do.