Dimensions & Spec of Front Spring Compressor

[ptjs1]

Having now decided to fully re-strip down the front suspension of my long-term restoration, I'm going to make a compressor for the removal and refit of the front springs. I remember that I followed the official Triumph Manual advice 25 years ago and just used a trolley jack for the strip and rebuild. It is interesting that the official manual said to just use a trolley jack whereas manufacturers usually err on the side of caution and recommend all the specialist tools! However, not only do I now better recognise the safety issues involved but I also remember the problems of refitting using a trolley jack to a car with no engine. It just wanted to lift the whole car up. I had to get a few people to sit on the front before eventually getting the springs in!

 

So, with the benefit of hindsight, the wisdom of age and the advice of nearly all members, I'm going to make a compressor for the re-rebuild. I've read all the threads available but still have a few questions:

 

- Everyone seems to suggest using at least M12 rod. M14 seems relatively hard to source, so is M12 sufficient or should I go for M16, which I can source easily? Will M16 more likely foul on the top or bottom?

 

- Is High Tensile 8.8 grade BZP acceptable or should I for an ACME thread?

 

- There seems to be a variety of bottom plates used by those that sell or have made such compressors. Thick alloy like the TRF one or thinner steel? Some are plain, some have the 4 holes for the shock plate nuts and some seem to have cutouts rather than the holes. Is it best to have 4 holes or would the cutouts better allow a bit of movement as it tightens up the spring? Has anyone got a template or accurate dimensions of the ideal bottom plate?

 

- Would studding connectors be better than nuts because of the amount of thread they cover? Is it necessary to weld together 2 nuts / connectors or can I just tighten them together?

 

- What size washers (thickness and diameter) should I use at the top?

 

 

Tks in advance for any suggestions.

 

Paul

[stuart]

If you have done the search you will have no doubt come across a picture of mine and a piece of angle iron works fine on the bottom and the washers I have are from a MK2 Jag panhard rod so quite thick but double nuts are fine and ordinary thread is easier than ACME as thats too coarse.Cant remember the size of the thread but it needs a 15/16" spanner and socket. Basically the largest thread that will comfortably pass through the hole in top of the turret is the best.

Stuart.

[Blue cedar]

Paul

 

The usual supportive culprits on this forum gave me advice. I have just stripped down and reinstalled my front suspension. It was a breeze. I happily over engineered buying an on line 1m length of threaded HTS 16m along with connector nuts. I used the wheels off my Halford's trolley jack as the plates top and bottom on the rod. The rod and nuts made the job a doddle.

[Kevo_6]

Hi Paul

I used 16mm threaded high tensile bar, I had some spare 25 x 40mm flat aluminium bar for the bottom with 2 nuts underneath the aluminium with a large washer and at the top I used a large washer, standard nut underneath a castle nut with a R spring clip. Oh and plenty of grease on the bar and nuts. All worked for me with no dramas.

Edited March 16, 2016 by Kevo_6

[openroad]

Hi Paul, i aslo have just done my front suspension, i started with a homemade threaded bar as you suggest, i now realise that a finer thread on the bar would have been far better and longer lasting , as i knackered the coarse thread......

Luckily for me , i borrowed a custom made Churchill tool from a great local specialist, and then it became a "Doddle", all done now and ready for a sunny day !

Good Luck,

Conrad.

[Blue cedar]

Conrad, hope your good.

 

That home made kit looked plenty strong enough to me. Have not had the chance to replace the Pheonix manifold with the original yet !

 

Cheers

[openroad]

Hi, Am well thanks. i still managed to strip some threads, rendering it pretty useless !

Always some thing to work on ,with these lovely cars of ours !

Conrad.

[Ragtag]

I'm about to make my own spring compressor as others have done. I'd quite like to make the bottom plate in the 'rectangle with holes/notches that line up with the shock absorber mounting bolts' style.

 

Unfortunately, I cant get to my car to scrabble around underneath at the moment so does anyone have a dimensioned drawing of such a plate or at least could give me the diagonal centre to centre measurement for the bolt holes?

 

Thanks in anticipation

[ed_h]

Rag--

 

I didn't measure on the car, but measured the plate on the compressor I made, and the slots fit over a bolt rectangle of dimension 1-5/8" x 3".

 

Ed

 

[rog1]

http://tr6.danielsonfamily.org/Files/SpringCompressor.PDF

 

Need to copy and paste the whole link rather than clicking on it.

Edited November 28, 2016 by rog1

[Ragtag]

Thanks Rog and Ed. Between you that seems to cover it

[ptjs1]

Chris,

 

I used the Danielson family template but either the tolerances are very tight or else my measurement and cutting isn't that good(!) but I ended up needing to fettle the plate and elongate the holes etc.

 

I am due to go down to the storage unit where my car is later this week and can make a fairly accurate cardboard template which I will post back here if that helps you.

 

Cheers

 

Paul

[Ragtag]

Thanks for the offer Paul.

 

I used the Danielson template and checked it against the measurements provided by Ed_h. The two sources agree but in any case, I drilled the holes at 13mm rather than 0.5 inch so there is a little wriggle room.

 

I haven't had a chance to use mine yet as I'm on pre-Christmas painting and decorating duty but hopefully I'll get into the garage between Christmas and the New Year.