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Moss J-type overdrive conversion bracket


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Good morning,

I'm about to fit a J-type gearbox and overdrive (ex-saloon, converted to TR spec) to my TR2. I bought the Moss conversion bracket kit, but on trial fitting the various bits, the chassis bracket fouls the exhaust pipe. I would have to space it by about 7mm to clear. This can't be right? I've scoured the forum and found one poster who had the problem, but no answers or pics. Has anyone done this recently?

Also, my centre exhaust bracket doesn't look like any of the options in the Moss catalogue. There was a rubber strap between the bracket and the original gearbox mount which I have removed, so the remaining setup would allow vertical movement I should think. What's the preferred bracket for this case?

Thanks in anticipation!

Brian

Gearbox cross member.jpg

Exhaust bracket.jpg

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Hi Brian,

As I do not own a TR2 I can only make an observation.

Looking at your photos and then the Moss “Bible” it seems to me that the remaining bracket consists of items 27 to 32 and is noted as a fitment for the TR3.

I think the parts that you have removed were the original TR2 exhaust fittings – items 21, 12 & 13 plus bolts.

I wonder if it is possible that fitting a TR4 type bracket would clear the new overdrive support as it sits to the side and firmly secures the exhaust both horizontally and vertically...?

Regards, Richard

 

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The TR4 bracket, which bolts directly onto the top of the gearbox rubber mount works very well, & allows the exhaust pipe to follow any movement of the engine / gearbox.

   post-12009-0-96201000-1475485979_thumb.jpg   post-12009-0-28227500-1503657668_thumb.jpg   post-12009-0-58196500-1503657668_thumb.jpg

Bob.

Edited by Lebro
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Richard,

I agree the exhaust bracket looks similar but not the same as item 27, and the strap item 21. However the main issue is that there is little clearance below the exhaust pipe where it passes through the hole in the chassis cruciform, so whichever bracket I use wont help with the gearbox mounting issue.

Bob,

Moss recommend the TR4 exhaust bracket but, and your pics confirm, thanks, it bolts to the overdrive mounting which is considerably different on the J-type to the A-type.

This shows the various components in the kit https://www.moss-europe.co.uk/bracket-fitting-kit-overdrive-conversion-j-type-to-a-type-211361x.html

Brian

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Brian, Like you I use the original style of exhaust mount on my TR3 and TR4 both with A type overdrive, I carefully hammered a dent in the front pipe to ensure clearance to the overdrive but there again it is a different set up. There are different front pipes for overdrive and non overdrive I think.

If it is a just touching event then a careful massage with a hammer should do the trick I expect, give it a few mm clearance though. However my experience is A type OD.  John

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Brian, I just recalled on my TR4 the exhaust rattled in the hole where it goes through the chassis. I did an adjustment of the original bracket by cutting and welding to optimise the position of the exhaust. The improvement to the car was immense. I recommend that you take time to 'thread the needle' now whilst it is bits.  Sorry no pictures. John

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5 hours ago, john minchin said:

Brian, Like you I use the original style of exhaust mount on my TR3 and TR4 both with A type overdrive, I carefully hammered a dent in the front pipe to ensure clearance to the overdrive but there again it is a different set up. There are different front pipes for overdrive and non overdrive I think.

If it is a just touching event then a careful massage with a hammer should do the trick I expect, give it a few mm clearance though. However my experience is A type OD.  John

Hi John, it's 7mm clearance I'm looking for, so not a hammering job. I called Moss this afternoon but they are on a skeleton staff and no-one could help.

I think I'll try assembling everything on the back of the overdrive tomorrow, take some measurements and try to work out where the centre of the output flange would end up if I use spacers under the bracket.

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I think I see where it is touching. It is because the bracket that goes across the car is lower in the middle, a standard one is flat. My suggested hammering would be where the joint is, so no good at all.

Judging by the pictures on the Moss website I would be very tempted to do abit of cutting and welding of that large bracket as it is only used to support the gearbox where the round bush sits. i.e. keep it higher over the exhaust. There seems to be fair bit of space under the OD casting. Brian - see your PM.   John

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43 minutes ago, barrytr4 said:

Hi Brian

Does the "J" type o/d actually fit  in the chassis? I tried one in my Tr4 , the solinoid was fouling the chassis--Barry

Yes it does fit but the new mounting bracket may need fettling to give clearance.  The bracket is already relieved but I had to remove more metal to get an adequate gap for the solenoid, and I seem to recall using  a packing plate on the rubber mount to raise the box a wee bit too.

Edited by RobH
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8 hours ago, RobH said:

Yes it does fit but the new mounting bracket may need fettling to give clearance.  The bracket is already relieved but I had to remove more metal to get an adequate gap for the solenoid, and I seem to recall using  a packing plate on the rubber mount to raise the box a wee bit too.

With my TR4, I had to make a similar mod to extend the cutout for the solenoid to improve clearance and likewise, I also packed up under the rubber mount to raise the whole gearbox a little - IIRC, my kit included some extra washers for going under the mounting for just this reason, but they were a devil of a job to fit!

I also made an exhaust bracket from a piece of angle iron, mounted under the front member bolt and going forwards, then hanging down enough to get a U bolt to fit to it vis an appropriate hole I drilled to take one of the threaded ends of the U bolt - unfortunately I can't get sufficient access to take a photo 

Cheers Rich

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An update:

I've fitted the mounting kit to the back of the overdrive (not a very good photo). It clears everything, solenoid etc. fine.

The height from the underside of the new cross member flanges to the centreline of the propshaft flange is 90mm. The height of the propshaft tunnel is 125mm. So as the propshaft diameter is 50mm, this would give 10mm clearance on the prop. Fine.

BUT, to clear the exhaust pipe (by only 2mm) I would need to raise the cross member with spacers by 8mm. Thus reducing propshaft clearance to 2mm. And that's just in theory, too close for comfort!

My conclusion is that this kit is no good for early cars. From TR4a onwards there's no cruciform box section that the pipe has to pass through so it probably sits lower and is not an issue. 

The Rimmer version looks 'flatter' but is v expensive...https://rimmerbros.com/Item--i-211361X. I'm tempted to try this one listed on eBay, which looks very (maybe too) simple: https://www.ebay.co.uk/itm/TRIUMPH-TR-6-5-4-3-2-73-J-TYPE-OVERDRIVE-CONVERSION-FITTING-PLATE-211361-5-11/393054420240?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649

So the box is not going in this year :angry:. Re the exhaust bracket, it looks like part 114074 would do the trick, it's looks the same as what I already have but with an additional mounting to the other chassis rail.

I'm surprised no-one has actually tried this kit, as Moss say they have sold loads!

Brian

Moss gearbox bracket.jpg

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That uses a small chassis triumph overdrive mounting, GT6/ Vitesse etc. Seems a lot simpler.  Mountings are only £12 or so, and the bracket is cheap enough. Might be worth giving it a try and if it works get your money back for the other bracket. 

It still seems to crank down a lot though between the chassis rails, which I suspect is where you are losing the exhaust clearance as the standard bracket is flat across the chassis.

Ralph.

Edited by Ralph Whitaker
Additional paragraph.
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Brian - I have the Moss kit fitted in my TR4 with a Stag box and J type overdrive - yes it was a bit of a fiddle, but I did get it to fit and its been in situ successfully for the last 5 years - you say you want an 8mm clearance for the exhaust which sounds a lot to me, particularly when space is so tight - do you really need that much- I was working to less than half that we no apparent downside.

I can't vouch for the other kits, but if they work, then that's great and a certainly a more cost effective solution- be interested to hear of others' experiences

Cheers Rich

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13 minutes ago, Ralph Whitaker said:

it still seems to crank down a lot though between the chassis rails,

It has to, to clear the solenoid. Brian's picture above is with no weight on the bracket. I think In reality the far end of it sits quite a lot higher than the picture implies so it is much closer to the solenoid.  

This is mine during a trial fit while I was working out how much more metal to remove. (The plate on the top is my addition to stiffen it up a bit to compensate for the loss of area - there is a simi lar thickness piece underneath which lifts the bracket clear of the exhaust. 5mm I think).

solenoid.jpg.9007de8cc10d9ce3537bef841f64e650.jpg

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57 minutes ago, rcreweread said:

Brian - I have the Moss kit fitted in my TR4 with a Stag box and J type overdrive - yes it was a bit of a fiddle, but I did get it to fit and its been in situ successfully for the last 5 years - you say you want an 8mm clearance for the exhaust which sounds a lot to me, particularly when space is so tight - do you really need that much- I was working to less than half that we no apparent downside.

I can't vouch for the other kits, but if they work, then that's great and a certainly a more cost effective solution- be interested to hear of others' experiences

Cheers Rich

Rich, you misread me - I said I would have to raise the bracket by 8mm to get 2mm clearance on the exhaust. The Moss kit seems to have changed at some time - the picture in the catalogue is different - I wonder if yours was the older design?

Cheers, Brian

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59 minutes ago, RobH said:

It has to, to clear the solenoid. Brian's picture above is with no weight on the bracket. I think In reality the far end of it sits quite a lot higher than the picture implies so it is much closer to the solenoid.  

This is mine during a trial fit while I was working out how much more metal to remove. (The plate on the top is my addition to stiffen it up a bit to compensate for the loss of area - there is a simi lar thickness piece underneath which lifts the bracket clear of the exhaust. 5mm I think).

solenoid.jpg.9007de8cc10d9ce3537bef841f64e650.jpg

Rob, interesting - how much clearance on the prop did you get with 5mm spacers? 

I'm also wondering if my exhaust might be big bore, it's a Double S system.

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3 minutes ago, Brian Eldred said:

how much clearance on the prop did you get with 5mm spacers? 

 

To be honest I never measured it because it just didn't seem a problem. It's well within the tunnel and it must be enough as there is no clonking.  At a guess a good 10mm over the flange.  After all, that end of it isn't going to move much - it's the diff end that moves. 

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Brian

Had the same problem with my installation  not helped by having the Phoenix big bore  system 2" dia with the 4 branch manifold

I fitted 6mm spacers under each side to get clearance on the exhaust  pipe  also enlarged the hole in the cruciform both ends for clearance.

The slot in the side for the solenoid needs opening out for more clearance as i was concerned there was not enough if the rubber mounting settled 

regards Adrian

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Thanks Adrian, 

My pipe is also 2" diameter so similar, though I need 8mm spacers to get 2mm clearance. It seems to clear the hole in the cruciform OK, though not much clearance at the bottom. I've modded the exhaust bracket to be like the TR3 type and ordered some bushes and bolts so will check again when that's mounted properly.

The Moss kit does seem to need a lot of beggering about though! I might try the one I found on eBay, which is an almost flat plate with a GT6/spitfire type rubber mounting. And cheap.

Brian

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Brian 

I was going to make an adaptor myself using GT6 mounts and flat plate but when i collected my refurbished box ( Dolomite Sprint  with J type od/)from Pete Cox he had already got the Moss type mount so i went with that. On reflection with the time lost messing about would have been quicker to have made my own 

Regards Adrian 

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1 hour ago, Adie TR3A said:

Brian 

I was going to make an adaptor myself using GT6 mounts and flat plate but when i collected my refurbished box ( Dolomite Sprint  with J type od/)from Pete Cox he had already got the Moss type mount so i went with that. On reflection with the time lost messing about would have been quicker to have made my own 

Regards Adrian 

Precisely what we did years ago in the TR2 using the GT6 mount.

Strip of steel on the chassis and the rubberised coat hanger fitted between the two.

Eventually went back to A type overdrive as the exhaust routing and the solenoid closeness to the chassis was unacceptable. Still have the J type o/d & gearbox assy 'just in case'

Cheers

Peter W

https://www.mevspares.co.uk/OVERDRIVE-GEARBOX-MOUNT-Triumph-Spitfire-and-GT6-1962-80.html

image.png.752a97d006a6b003b0d5a956c5539cc9.png

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Interesting post,

the weight is based on the Moss crossmember behind the the standard crossmember.

This gives all load on the rear ends of the brackets welded on the frame and lifts their fromt ends up.

I guess this us without any problem for the frame and welded brackets?

How much centimeters is the weight beared behind the standard crossmember, please?

This could be an easy way to fix my MX-5 gearbox!

Ciao, Marco 

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I woul

15 hours ago, Z320 said:

Interesting post,

the weight is based on the Moss crossmember behind the the standard crossmember.

This gives all load on the rear ends of the brackets welded on the frame and lifts their fromt ends up.

I guess this us without any problem for the frame and welded brackets?

How much centimeters is the weight beared behind the standard crossmember, please?

This could be an easy way to fix my MX-5 gearbox!

Ciao, Marco 

I would guess the GT6/Spitfire overdrive application mounting plate to the chassis moves the mounting back by 5cm.

The TR6 non overdrive gearbox when fitted in a J type overdrive chassis has a right angled bracket (item 54) to fit between the J type mount point and the non od gearbox mount (which is identical position of A type overdrive)  It too is about 5cm.

Peter W

 

image.png.b1ed8e5d857a9d2def37cf93223dcd4f.png

The

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