Gearbox mount

[Robbie693]

Hello,

Can anyone tell me if the gearbox mount (the rubber/metal bit) is different for a Spyder chassis please?

I know that the bracket is different but i thought the mounts were the same. I bought a new one from Paul Matty and it's not the same as the one I took off. It's a different physical size for one thing and the hole in the middle is too small for the bolt to go through. This I can drill out obviously but the thing that concerns me most is the difference in thickness between the bottom of the plate to the bottom of the channel in the rubber - it looks as though there will be a space between the mount and the support bracket..

Pics attached as I'm not so good at explaining things:

[GrUmPyBoDgEr]

They both use the same mount but you will need to drill out the centre Hole, that's what I did.
Your old mount has just swollen so the new one will be OK.

John

[gerrym]

Robbie, I know this a bit of an aside, but I added Rivnuts to the gearbox mounts. I can now screw the fasteners in from below without trying to get a spanner in and hold the nut. (Not enough room on the Spyder MT75 setup for a spanner or a socket).
I did think about welding the nut but this might damage the rubber bonding (probably be OK with TIG)

Regards

Gerry

[GrUmPyBoDgEr]

Robbie, I know this a bit of an aside, but I added Rivnuts to the gearbox mounts. I can now screw the fasteners in from below without trying to get a spanner in and hold the nut. (Not enough room on the Spyder MT75 setup for a spanner or a socket).
I did think about welding the nut but this might damage the rubber bonding (probably be OK with TIG)

Regards

Gerry

"TOP TIP" Gerry!
It's a sod of a job with the standard G/Box, nearly a 2 Man job.
Cheers
John

[bcmc33]

I did think about welding the nut but this might damage the rubber bonding (probably be OK with TIG)

IMHO this is the best option to ease a pig of a one man job.

[CBUEB1771]

I bought a new one from Paul Matty and it's not the same as the one I took off. It's a different physical size for one thing and the hole in the middle is too small for the bolt to go through.

Robbie - I have gone through this recently. Someone has commissioned a reproduction gearbox mount and they are dimensionally incorrect exactly as you point out. I got one just like yours from one of the US suppliers. You can enlarge the center hole and then space the mount up off the cross member to restore the correct height of the gearbox. (Sorry Pelly Esq. there is more difference than just the swelling of the old one). I also noticed that the section that cradles the tail housing is much more shallow than on the original. An alternative is the stiffened road-going mount from TTR. I got one of these from RD Enterprises (TTR's US outlet) and this is dimensionally correct.

[GrUmPyBoDgEr]

I bought a new one from Paul Matty and it's not the same as the one I took off. It's a different physical size for one thing and the hole in the middle is too small for the bolt to go through.

Robbie - I have gone through this recently. Someone has commissioned a reproduction gearbox mount and they are dimensionally incorrect exactly as you point out. I got one just like yours from one of the US suppliers. You can enlarge the center hole and then space the mount up off the cross member to restore the correct height of the gearbox. (Sorry Pelly Esq. there is more difference than just the swelling of the old one). I also noticed that the section that cradles the tail housing is much more shallow than on the original. An alternative is the stiffened road-going mount from TTR. I got one of these from RD Enterprises (TTR's US outlet) and this is dimensionally correct.

I stand corrected Russ.
The old eyes 'aint wot they used to be & there's nothing better than "recent experience"
John Pelly Esq.

[Robbie693]

Thanks all,

I spoke to Spyder and they wern't aware of any difference with the new mounts. I measured the difference with a vernier and it's 1.75mm - not a lot really when you take into account welding accuracy of the actual chassis bracket? The difference is exagerated by the photos.

I figured it would be ok as Spyder use the current type of mounts as do Paul Matty (where I got it) so bolted it up.

Will it be ok?

Robbie

[gerrym]

John, here's a picture of the mount with the captive rivnuts added, a sample of the rivnut before it was "rivetted" in place and the tool I used.

The tool is beautifully constructed, really solid and can be used on variable thickness material such as fibreglass (sill shut fasteners?) http://cheapestrivnuts.co.uk/tools.aspx

For the gearbox mount, you might want to counterbore a recess in the matching mount or spacer: this is because the flange of the rivnut sits about 1mm proud and will cause the mount to rock. Then if you are really a&*l you could add lockwire or Nordwashers to stop the threaded fastners coming undone and falling out.

Regards

[alexblack13]

Hi Guys/ Gerry,
I am a great fan of the riv nut also and have used them in various locations here n there around the car. In the door for eg to hold the pull handles. On the radiator panels so just a set of 8mm dia dome headed s/s fasteners (with no nuts!!) holds the rad in place etc etc. I have not tried them on the gearbox mount... but I was going to try them in the engine mounts! What stopped me was the 'flange' that Gerry mentioned. Those nuts & (or) bolts holding the mounts are a real pig to get at. Fitting riv nuts or similar here would make life much easier..... Next idea was to square the holes and use a pair of captive clip in nuts in steel. Those will def' do the job.

Great fix Gerry.. My riv nut tool looks different to yours. It looks like a big HD pop rivet gun..

Great tool though..

Question..The insert/nuts are all aluminium alloy in my stock. Are they made in anything stronger? I have as yet to find any in anything other than Ali...

Good work!

Alex B....

[gerrym]

Alex, for the gearbox mounts the rivnuts are zinc plated steel. The whole lot will get some paint before it goes on the chassis.

For the top of the pedal box (to hold the closing plate and keep out the draughts), I'm using M4 aluminium. The sill closing plates will be done in M5 stainless.

Basically there's a massive range of styles and materials depending on the application, strength, corrosion etc.

The only thing is I havn't seen a huge range of UNF/UNC threads this side of the pond.

Regards

Gerry

PS, a very shallow counterbore will take care of the flange.

[GrUmPyBoDgEr]

Gerry,
thanks a lot for that information.
I've bookmarked that site so that I can make a purchase in the not too distant future.
I assume that the Kits come with just the Pliers & Aluminium nuts only.
Do you have any recommendations as to what to order in one sweep so to say?

Cheers
John

[alexblack13]

Great Gerry, Just spoke to Mrs B and she can get them in various sizes and materials. The tool I have is shown in the site also just below yours. It would appear that one requires a bit more 'pull' for anything other than the Ali nuts. Do you think M8 plated would be good for the engine mounts or go for M10??
I am going to upgrade to the same as yours.

Thanks again..Great site.

Alex..

[elanmac]

One of the trade names for the rivnuts is Bollof and they are available with a shallow countersunk head.

[bcmc33]

I've always recommended tack welding nuts on a bare chassis engine mounting brackets, but I see the benefits of rivnuts. M8 is an equivalent to 5/16" UNF, so I guess I shall go this route as the engine is out. And probably on the next gearbox mount.

One of the trade names for the rivnuts is Bollof and they are available with a shallow countersunk head.

B?llhoff in Bielefeld was a supplier to me in a previous lifetime - from memory the most impressive thing I remember was the manufacture of Helicoils.