32 replies to this topic

[mini-mad-mark]

Sorry I can see from your picture now that you have just fitted the pin into the inner position up to the thrust washer - weird - as you say seems like the subframe is too thick

 

Or as Moke Spider says just check the thread length of the pin is OK per the size he quoted (might be a duff pin)

[RustyAutoCityE]

 

Where the pin is fitted, the Subframe is laminated with (if memory serves) 3 layers. These may have spread a little. I don't know if in your top photo you've done the nut up, if you haven't, try that as that maybe the issue.

 

The Stub on the inboard end should be 1.050" from the Pin Shoulder. It might also be worth measuring.

I did tighten the nut on the top picture. Like you say it may pull in a bit when fully torqued. I’m just wandering why I measured the thickness of the subframe hole to be 10.5mm whereas Rusty measured his old subframe at just under 7mm?

 

In the morning i will fight my way to the new (pattern) subframe and get a measurement off of that too, will also check the other side of the old one, just out of curiosity.

[Spider]

 

Where the pin is fitted, the Subframe is laminated with (if memory serves) 3 layers. These may have spread a little. I don't know if in your top photo you've done the nut up, if you haven't, try that as that maybe the issue.

 

The Stub on the inboard end should be 1.050" from the Pin Shoulder. It might also be worth measuring.

I did tighten the nut on the top picture. Like you say it may pull in a bit when fully torqued. I’m just wandering why I measured the thickness of the subframe hole to be 10.5mm whereas Rusty measured his old subframe at just under 7mm?

 

 

Hmmm,,, OK. Check the stub length I guess.

 

Just to put it out there - your Subframe does appear to be quite sound, but it's not swollen from rust in there is it ?  Looking at your 2nd Photo, there does appear to be some separation between the layers. I really doubt this is the issue, but best check all the same.

[Mayfair94]

Where the pin is fitted, the Subframe is laminated with (if memory serves) 3 layers. These may have spread a little. I don't know if in your top photo you've done the nut up, if you haven't, try that as that maybe the issue.

The Stub on the inboard end should be 1.050" from the Pin Shoulder. It might also be worth measuring.

I did tighten the nut on the top picture. Like you say it may pull in a bit when fully torqued. I’m just wandering why I measured the thickness of the subframe hole to be 10.5mm whereas Rusty measured his old subframe at just under 7mm?

Hmmm,,, OK. Check the stub length I guess.

Just to put it out there - your Subframe does appear to be quite sound, but it's not swollen from rust in there is it ? Looking at your 2nd Photo, there does appear to be some separation between the layers. I really doubt this is the issue, but best check all the same.

I measured the stub length and it is about 1 inch without getting my verniers out. The separation is a good idea, it is a new subframe to me but may have been in the shop for a while? Looking at the hole I can’t see any separation, the hole looks good. What I did notice is there are from what I can see 4 layers of metal, which is more than a previous comment I think. There is the outer and inner ribs which form the support for the trumpet. Then there is a layer from the front cross member and then the bracket for the brake pipe. The total thickness is resulting in the thread showing to be smaller than usual (from what I can tell).

The thrust washer and shoulder of the pin are hard up against the subframe so what protrudes through the subframe seems to be what I have to work with. To be clear, this is a Magnum subframe and the one I removed I presume to be original.

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Edited by Mayfair94, 12 September 2020 - 09:11 AM.

[Spider]

It does look thicker than a standard one. These holes are a little renown for elongating, (but only if the nut's nit done up tight), maybe they have put an extra layer in to better cope with that ?

 

The length of the stub sounds about right.

 

If the Nut engages by around 3/4 of the thread in the Nut and you can get it up to Torque (50 ft/lb) then while not ideal, it should be fine.

[RustyAutoCityE]

Just went and got some quick and dirty measurments from the garage.

 

Presumed original subframe - both sides around 7mm thick.

 

Pattern Subframe - around 10mm (can only get to one side without dragging half the garage out).

 

Stub length - just over an inch.

 

Looks like I will have to deal with this in the future too....

[GraemeC]

Something like this might be an option as it is shake proof but would give you more thread engagement:

https://www.westfiel...LhoCTgoQAvD_BwE

 

(can't remember off hand what the thread size is on the radius arm pins)

[Mayfair94]

Thanks very much for your help guys. It sounds like it is thicker either by design, or just that it is a pattern subframe. Rusty, thanks for taking your measurements, they sound the same as mine so you may also need to make some adjustments.

I will de burr the holes as I noticed some burrs either side. I have ordered some 1/2 inch stainless steel nyloc nuts and may try these with a flat washer instead of the spring washer. I really wanted to avoid having to removed the radius arm I have already fitted as all the other holes lined up and have bolts in them and just need a final tighten/torque.

[GraemeC]

A nyloc may not work if you can't get the nut on far enough for the pin thread to reach the nylon section

[Spider]

,,,, I have ordered some 1/2 inch stainless steel nyloc nuts .

 

Please, don't use Stainless - it has next to no tensile strength.

1/2" UNF Grade 8 ZP is the shot, just a Plain nut, not Nyloc (which won't come in Grade 8 in any case). If you want to get more thread in the Nut, leave the Spring Washer off and put a dab of locktite on the threads.

[Mayfair94]

A nyloc may not work if you can't get the nut on far enough for the pin thread to reach the nylon section

Cheers Graeme, I’ll see how it fits and if it’s not in safety will remove an rethink.

[Mayfair94]

 

,,,, I have ordered some 1/2 inch stainless steel nyloc nuts .

 

Please, don't use Stainless - it has next to no tensile strength.

1/2" UNF Grade 8 ZP is the shot, just a Plain nut, not Nyloc (which won't come in Grade 8 in any case). If you want to get more thread in the Nut, leave the Spring Washer off and put a dab of locktite on the threads.

 

Cheers Moke, I’ll see what I can find and ditch the nyloc SS. Everyone’s advice appreciated, cheers.

[A-Cell]

The 2 thrust washers are different.
Outer washer is thinner 3.8mm thick
Inner washer is thicker 7.4mm thick and larger diameter than the inner one.
The pin has a longer thread at the inner end. Also has threaded hole for grease nipple at outer end.
Check thrust washers are correct and correct position.

Hmmm - can you edit that so it’s clearer?
the inner washer is a larger diameter than the inner one?

...inner larger diameter than outer! Sorry.
I edited my original post to clarify thrust washer dimensions, part nos and set up.

[humph]

Is this a new none genuine subframe? Talking to a couple of suppliers recently they have had loads of their none genuine subbies returned due to radius arm fitment issues. Appears that the manufacturer has subcontracted manufacture out and the new fabricator has made a bad batch. Because of this Minispares have started making their own rear subbies, there’s a post from Simon on here confirming this somwhere.

[Mayfair94]

Is this a new none genuine subframe? Talking to a couple of suppliers recently they have had loads of their none genuine subbies returned due to radius arm fitment issues. Appears that the manufacturer has subcontracted manufacture out and the new fabricator has made a bad batch. Because of this Minispares have started making their own rear subbies, there’s a post from Simon on here confirming this somwhere.

Yes this is a Magnum subframe, unfortunately Minispares had no stock of their subframes until October and I needed to get a subframe in before my Furlough finishes. The subframe is in and now doing radius arms. The radius arms can be installed with no issues, however the metal is thicker where the pin goes on the inboard side. This means not as many threads exposed so need to have a think and make sure nut is installed safely.