Just curious but when I do a search for the rear engine mounts on a Mk2 it shows two small rubber bushes, just wondered where they fit in as shouldn't it be a spring ?

 

There's the main mounting with a spring, and the engine steady mounting at the back of the cylinder head that has a couple of small rubbers.

 

They are part number C12677, whereabouts do they fit ?

 

Engine mounts generally aren't springs, they are usually some form of metal and rubber bonded structure, this applies to almost any engine mount, there would be way too much movement if springs were used.

There are 2 front mounts on the Mk2, the engine steady as Fraser has said, and the gearbox mount which does have a spring which has rubber seats that the spring sits in.

The front engine mounts are C4794, which oddly SNG have called "gearbox mount" and C4794# which they show as "rear engine mount", but as far as I am concerned should be either Front Engine mount or just Engine Mount as they are not at the rear and definitely not on the gearbox. The gearbox mount is CBC2517 for the rubber seats and C12265 for the center bush.
The top stabiliser is C20218, but it is part of the stabiliser assembly which comprises several other parts, but this is the part that usually wears.

 

AH, those are for the auto gearbox, is that what you have ?

 

Thanks for reply TilleyJon, no I have a had a Tremac T5 conversion and looking to alter the rear engine mount or gearbox mount as I prefer to call it and looking for alternatives to replace the spring. Do you know if the Moss box uses the same mount as the later full synchro unit ?

 

Can you post some pics of what you have at the moment ?

Also, what is your chassis number as I'm not sure exactly what car/year we are discussing.

 

She is a 1966 3.8, not matching numbers. Garage that did conv fabricated a mount but used a solid rubber mount, think from a xj6, but this transferred to much vibration so replaced rubber with original spring which has greatly reduced vibration but has made the mount to low. Spoke to CMC and they haven't done a T5 conv but the Supra gearbox conversions they do they use a twin rubber bush mount which is what Thunderroad Speedshop in Horsell have advised. Just wanted to get an idea of what rubber mounts to use and other peoples ideas on the subject. Going to have the prop sent off to be balanced at the same time. The auto box also uses a spring with a different mount to the manual according to SNG website but I can't seem to find where part number C12677 'gearbox mounting bush' goes.

 

Just found this description on SNG but under the MK1 rear engine mount title which has that part number; REAR MOUNTING (RUBBER) BETWEEN BRACKET FOR REAR GEARBOX MOUNTING AND REAR ENGINE MOUNTING ASSEMBLY.

 

Just found it under the MK2 title under rear mounting automatic gearbox but can't see it on the diagram at all so not sure where it is supposed to sit.

 

This part was used up to mid 1964, with the earlier mounting plate, Plate(fig) 52 in the parts catalogue page 187. The bushes do not show on the diagram, but by deduction they seem to fit between the mounting bracket (17) and the gearbox, bu I am not 100% sure.

I am not familiar with the T5 conversion, but having a look at this, the Tremec gearbox does mount using 2 bobbin type mounts like C12677, but I cannot find how these sit with reference to the/a mounting bracket.
(just found a picture on Wilkinson website of the kit which appears to have an adapter plate which fits to the 2 mounts and than I assume to the existing support plate)

I am also unsure why the mount would be low if you have put the spring in place, the support beam is fixed to the chassis, so I would have thought the spring would have raised the gearbox tail up rather than down, but obviously you have a fabricated mount, so without pics I am not sure what issues you have re the spring, or how to best advise.

 

The T5 is sitting lower than a standard gearbox so the original mount can not be used, they have used the original spring but fabricated a new mount. Want to use something else to raise the height of the mount and wondered if the rubber bushes C12677 would work but would like to know the original purpose of them first. My parts book must be different to yours as those plate and page numbers don't match up, plate 52 part number 17 is a ' bracket for rear gearbox mounting ',part number C12577, is that what you mean? It then states that part number C12677 is ' Rear mounting(rubber) between bracket for rear gearbox mounting and rear engine mounting assembly '.
So does that mean that the rubber bush sits between the bracket (C12577) and where it attaches to the gearbox ? They're not expensive so I may just buy a pair and take them down to the fabricators who do a lot of this sort of thing on AC Cobras and Hotrods/ American muscle cars and see what they think.

 

You have the correct page and part no's, and yes that is how I think they fit.

Without some pictures, it is almost impossible to see what you are trying to achieve, is the fabricated mount under the T5 ? You say the T5 is sitting lower than the standard gearbox, then you say you want to raise the height of the mount, I have no idea if you are trying to raise the T5 as I can't envisage how the fabricated mount works.

On the ones I have seen, there are 2 lugs on the lower edge of the T5 toward the rear end, the 2 rubber mounts fit in those and then onto a bracket that comes with the conversion that then fits to the original bracket somehow. If yours doesn't use the original bracket, it seems that whoever fitted it didn't use one of the kits.

A picture speaks a thousand words as they say.

 

This is a shot of the first one they did with the solid rubber mount but this caused too much vibration so the rubber mount was changed for the original spring which has greatly reduced the vibration but has made the mount even lower than this one. What I am after is finding out if those two smaller rubber mounts C12677 could replace the spring and raise the height of the mount while keeping the gearbox the same height. CMC use two rubber mount on there Supra gearbox conv but have not done a T5 conv so could not advise but did say that it was common to have a vibration issue when doing a gearbox conv, the firm that did the work , I have since found out, had never done a T5 conv either. Thunderroad Speedshop came up with some issues with the current mount and bracket straight away including the agricultural look of the thing.
By the time the T5 is installed and the metal conv plate is bolted on it is sitting to low to get the original gearbox mount bolted in so they made this up. We may be able to tilt the gearbox up a fraction but your only looking at 1in tops before it starts to hit the gearbox tunnel.

 

Take a look at Wilkinsons, Gearbox and clutch ? M&C Wilkinson scroll down the page you will see the T5 kit, it would be worth giving them a call and see if they can help, they supply 2 mounts like the C12677, so they must have a solution.

Let us know what you find out.

 

They reckon that those small bobbin type rubber mounts like C12677 are fitted instead of the spring with the original mount. Won't be able to see much until it gets on a ramp and will let you know how it goes. Thanks

 

That makes sense, looking at the picture on their site, it looks like the bracket attaches to the T5 at the 2 holes nearest to the rear of the gearbox, and the 2 other holes on the wider part of the bracket take the 2 bobbin mounts, I will take a look at my rear mount cross member and see if there are holes that will take the bobbin mounts.

You may have to purchase the bracket from Wilkinson's to achieve what you want, as it looks like that bracket would fit closer to the gearbox and give you the room, they have obviously done this many times so it must be a tried and tested resolution.