Differential mounting pins

[nitronig]

158936.jpgcan any body answer a question regarding the locating pins for the differential mounting plate. the question is :-why are they made as long as they are. i have had to fit some new ones and had to cut them down . have i fitted them wrongly or is there some other way of fitting the pin that i dont know about .

[Duncan Skye]

Hi there,

I can't enlarge your piccy to get a proper look at that bolt, but am assuming it's item 158936, (two off) which protrude down from the underneath of the car. There's something in the dark recesses of my mind that suggests they were welded on to the shell and protrude down through it. Unfortunately I can't physically check at the moment.

If these are the right bolts, there are a couple of fairly thick bushes which fit either side of the two cups on the diff mounting plate. They're quite meaty and take up a lot of the length on the bolt. Rimmers Catalogue, Page 62 carries a good illustration if that's any help. If this isn't the bolt you're talking about, come back with some more info, or check to make sure you're not using 158936 in an incorrect location.

Sorry to be a bit vague, but I'm doing this from memory.

With best wishes,
Duncan, Skye

[Bob Heritage]

The bolt protrudes 2 5/8" below the bodywork, 2 bushes the diff hanger and the thick washer takes up 2 1/4" and the nylock nut takes up the remaining 3/8".

[nitronig]

heres before


and after


and with the diff in place

the new pins are from rimmers but they look the same from every were. on my first attempt replacing the pins i ground the old ones off and just welded the new ones in place. it wasnt until i tried to hang the diff bak up that you find they are too long .the nuts hit the end of the thread before pulling up tight on the bushes . if you know what i mean. second time as per the picture i cut them down to the same lenght as the old ones and welded them onto some plate first then onto the body . this time they pulled up nice and tight . i know i should maybe have checked them first .but you buy items in good faith thinking they are correct . surely the can be machined smaller in the manufacturing process or have i fitted the incorrectly.

[dasadrew]

It's not clear from your pics, but aren't those studs meant to be inserted from inside the car under the rear seat/tonneau pan on top of the floor panel? I might be hallucinating, but I feel sure there is a grommet in the crossmember at the back of the tonneau well where you can see the top flange of that stud in the box section. Sorry if that's b0ll0cks - working from memory at the moment...

[nitronig]

i dont think there is any way of locating them from inside the car . but i will go have a look and check.

[jbuckl]

Yes, they should be fitted from above.

[dasadrew]

I've had a scan of my car pics (at work at the mo) and I can't see any sign of the stud 'head' nor the part 153421 on the underside of the car, just a weld bead going around the stud shank. Memory might play tricks, but I'm sure the stud head thickness, that special washer thickness and the thickness of the cross-member steel might account for the length difference you mention.

Diff Hanger Stud.jpgDiff Hanger Stud 2.jpg

[Guest]

When I changed my mounting plate, I asked Paddocks about getting new pins - mine were nothing like as bad as yours. I was told that they are welded in from above during manufacture. I had a look and sure enough, they had been inserted from above. I was also told that it is not a separate part for a Stag, but it is for the 2000, so maybe they are slightly different. I just cleaned mine up and refitted everything.

Anyway, you've got them in now, so you're good for another 40 years!

[nitronig]

I will have a look today at some point to see if there is any way to fasten them from above .i am sure it is a chissis box section and you cannot get access

[jbuckl]

iirc head and weld access is under tonneau cover.

[StagnJag]

I think you would have to open up a hole inside the car, just in front of the rear bulkhead to gain access.

Rgds

Dave

[nitronig]

if they should be fitted from above does anyone know how it is done ?

[les M]

I will have a look today at some point to see if there is any way to fasten them from above .i am sure it is a chissis box section and you cannot get access

Nitronig
The mounting studs/bolts do indeed go through the box section, they are welded to the floor section behind the rear seat then go through the box section and are welded to the underside of the box. I think from memory that the box section is approx 3" deep. I think that welding only to the bottom of the box will not give enought strenth to the mounting as the forces applied by the diff will try too push the pins back, I think if triumph could have got away with only welding to one section and not both then they would have?
Just my thoughts on the subject

Les.

[Duncan Skye]

Hi there,

Looking at my old shell, you can see the 'D' shape of the heads of these bolts through the arrowed hole. It looks like they were dropped into the box section so that they protruded through their locating hole, then were welded from underneath, around the hole they dropped through.

Cabin Aft 2.jpg

I hope that's of some help.

With best wishes,
Duncan, Skye