18 replies to this topic

[PACINO]

I have these two holes with the thread passed. If I put the screws, they are not tight, so if I brake hard, the car is out of square. The best solution?

Regards, Luis

[MiniMadRacer]

Subframe out for that repair I am afraid, or... you could cut a hole in the panel infrontt of the rear wheel and put a nut and bolt in it, then repair the panel you just cut a hole in and  repaint it, but it would be a bugger to replace the subframe in the future..

[MiniMadRacer]

And as a side issue, I would not be trusting that jack on its own, I hope you have axle stands under that motor

[weef]

The repair will depend on what skills you have to hand. 

Option 1     drill out with the next size up tapping size, thread the fixing then carefully drill only the bracket with the clearance size drill. Fit the new over size bolts.

Option 2     drill out and fit a helicoil of the same diameter/thread as the origonal fixing.

Option 3     Cut out the bottom of the subframe to give access, then either using longer bolts and nuts or a piece of bar drilled and tapped at the correct centres, fit it and tack weld in place. Weld a patch to the subframe .

 

Hope this gives you some ideas to make the repair.

[Cooperman]

The threads are in trapped nuts in the sub-frame face, not in the heel board.

The way to repair that is to remove the radius arm which will expose the bolt holes with the stripped nuts on the inside.

Cut a rectangular hole so that both the holes/trapped nuts are removed.

Make up a rectangulr plate with two 5/16" UNF nuts welded on the inside to sit in the rectangular hole with and weld all around the edge to secure it. When I had to do this, I added a doubler at each end which located the plate and added strength. 

Linish back paint and re-fit the radius arm. 

If you need a drawing of how to do this, PM me your email address and I'll do a drawing.

It sounds more difficult than it is.

You can't do this by cutting a hole in the sill as that is only for access to the trapped nuts for the sub-frame trunnions, not the radius arm brackets.

[Cooperman]

The threads are in trapped nuts in the sub-frame face, not in the heel board.

The way to repair that is to remove the radius arm which will expose the bolt holes with the stripped nuts on the inside.

Cut a rectangular hole so that both the holes/trapped nuts are removed.

Make up a rectangulr plate with two 5/16" UNF nuts welded on the inside to sit in the rectangular hole with and weld all around the edge to secure it. When I had to do this, I added a doubler at each end which located the plate and added strength. 

Linish back paint and re-fit the radius arm. 

If you need a drawing of how to do this, PM me your email address and I'll do a drawing.

It sounds more difficult than it is.

You can't do this by cutting a hole in the sill as that is only for access to the trapped nuts for the sub-frame trunnions, not the radius arm brackets.

[dyshipfakta]

I cut a small flap in the sill and put bolts on the back and welded the flap back up. It means next time the subframe has to come out I will have to cut my welds again but was a quick easy repair. Flap doesn’t have to be big just big enough for a spanner an inch or so square

[Cooperman]

That works for the sub-frame trunnion bolts, but not for the radius arm bolts because the rad arm brackets bolt to trapped nuts inside the sub-frame box section rather than the heelboard.

[dyshipfakta]

That works for the sub-frame trunnion bolts, but not for the radius arm bolts because the rad arm brackets bolt to trapped nuts inside the sub-frame box section rather than the heelboard.

Yeah your right need to look at pics abit closer next time. I had just woken up in my defence night shifts lol

[PACINO]

And as a side issue, I would not be trusting that jack on its own, I hope you have axle stands under that motor

Thanks for your interest MiniMadR. The jack is from Germany and very strong. Anyway, the best way to work safely is to put some axle stands underneath.

Cheers!

[PACINO]

Thanks to everybody for the help, especially Weef and the master Cooperman. I don't know weld and Iven't got equipment to do that, so I think I'll choose to insert a 'Helicoil'. The problem is that the original thread is not very 'deep'. I have seen with the torch, the hole is about 2 centimeters deep but there is less thread. With which I don't know how strong and secure that will be.

Regards

[Ethel]

You could take the subframe off so you could access the back and take it somewhere to get it welded, but you'd run the risk of hitting similar problems with the  bolts holding the subframe to the car!

 

I wouldn't be very happy to helicoil that as there's not that much metal on the other side.

[PACINO]

Hi Ethel, great photo to see the inside of the piece. Thanks a lot man! You're right, there's not much metal to insert a helicoil to consider a job finished forever. The ideal would undoubtedly be to cut out the damaged part and weld a rectangular metal strip with two new threads just as the colleagues said yesterday.

Regards!

[MiniMadRacer]

You are right Cooperman, I was looking at the wrong nuts.....forget my post / comments they are wrong

[Cooperman]

The old threads are 5/16" UNF. You could take the rad arm bracket off and drill and tap the stripped nut(s) to M8 Fine thread, then just drill out the holes in the bracket to 8.5 mm or even 9 mm and fit some short socket head cap screws. That is what I would try first as I think it would work fine. That is only about 1 hour's work once you have your tools ready. I would use a socket head cap screw as it might be difficult to get a 14mm AF socket onto those oversize bolts plus a socket head screw will remind you that these are the oversize threads. Make sure it's an M8 FINE thread, as the coarser thread might not give sufficient strength.

 

Last year I had a rear trunnion trapped nut strip and I did cut a rectangular hole in the sill just forward of the heel board. The hole was about 2" x 2.5" and it was then easy to fit a new not and get the welding torch in to trap it permanently.

Then I just flush fitted a patch back into the sill and re-painted it.