Amazon: Gearbox mount - where am I going wrong?

[PenR]

Hi Guys - just spent 4 hours on my back in -1 temp failing to change my gearbox mount on my 1967 B18 non overdrive 122s.
I'm in rebuild mode and having put my engine back in on new mounts decided that the rear gearbox mount was ok. However whilst fitting my new complete Simonz exhaust (v.nice thanks Simon) noticed a split in the rubber. I already had a new mount that was at the bottom of a box of spares that came with the car.
I undid the 4 bolts holding the gearbox xmember and the single nut in the centre for the mount after supporting the gearbox with a jack. No probs thus far then. Unbolted the old rubber mount and its bracket from the rear of the box - attached it to the new mount and reinstalled on the gearbox Offered up the crossmember and no way could I get the bolts to line up with the holes. Checked that bracket was the right way up - tried every combo and can only get one side to line up loose.
Now, I allegedly know what I'm doing (I restore Porsches) but I just don't get this at all - I checked the Haynes manual (nothing there then) and various diagrams but still no go.
There must be a sequence other than what appears obvious to me. It should go in like a greased cougar from the planet big bol...ks!
What am I missing here?
As usual I'm appealing for help and if you feel like calling me an idiot - please help yourself, cos I feel like one
Thanks in advance
PenR

[amazon69]

Get another jack and use that to persuade the alignment, or use a long screwdriver through one of the mount plate holes and into one of the body holes to lever alignment that way...that allows you to get one bolt in on the difficult side, then the other's easy. I've had similar. PITA.

[PenR]

Ta for that - I had kind of figured that leverage might come into somewhere but can't figure why it was so easy to remove. The plates either side of the Transmission tunnel can't move so.....
Any road up, thanks for the help - its somewhat gratifying to find that someone else has had the same problem as I thought that the cold had affected what passes for my brain!!
Time to root out that spare scissor jack!!!
Cheers mate
PenR

[Volvo_133]

Hi Pen R,
Also had same trouble, and used screwdrivers in holes to help line it all up. I changed 2 engine mounts and 1 box mount to poly.Car drove as though mountings were made of concrete.Left poly at gearbox and went back to rubber at engine,now OK.
Digressed slightly,could also try using 2 longer bolts in the diagonal mount holes.Also try with rubber mount nut loose.
good luck,
Chris.

[PenR]

Thanks again - I'm on all brand new rubber. Considered going poly but didn't and by the sound of things I'm rather glad I didn't do it. I had a customer who had us change all his engine and transaxle mounts to poly on his 924 turbo - it was so bad that it vibrated his CD player into constant eject! Not only that but there was certainly no improvement in performance - expensive too!
Thanks again
PenR

[simonvolvo]

In case you haven't solved the problem yet, this is what I always do (I have a chain block hanging from the rafters in my garage):

Loosen the front engine mountings, and hoist up the front of the engine until it just starts to lift off the engine supports. It is then dead easy to line up the gearbox cross member and bolt it on.

[PenR]

Hello Simon?
Thanks for the help - I get what you're saying here but the physics defeat me - lift the front of the engine and the gearbox drops lower by my reckoning. On the other hand I suppose it puts more flexibility into the engine/gearbox unit as in up/down and side2side.
Its like -5 here so I blew out today but I'll give it a try tomorrow and report back via the thread
Ta
PenR

[volvonic272]

Will try to pm you mate.

[Bladerider]

Had similar problem on mine. Then remembered the engine mount holes were slotted on the Xmember so lossened these then used a suitable sized screwdriver for leverage on one side of the g/b mount, the other having one bolt loosely inserted.

[simonvolvo]

Originally Posted by PenR

Hello Simon?
Thanks for the help - I get what you're saying here but the physics defeat me - lift the front of the engine and the gearbox drops lower by my reckoning. On the other hand I suppose it puts more flexibility into the engine/gearbox unit as in up/down and side2side.
Its like -5 here so I blew out today but I'll give it a try tomorrow and report back via the thread
Ta
PenR

Yes, Simon it is.

It's not up/down and side/side that is the problem. It's back/front.

The front engine mountings are not quite vertical. They lean over to the back a bit. This, and the fact that the mountings are by their nature flexible, causes the engine/gearbox assembly to move down and back a little when the gearbox mounting has been removed. (The gearbox mounting is also not vertical but leans over to the front. When in place, it opposes the tendency of the engine to move back.)

When you want to put the gearbox cross member back you have to push the engine/gearbox forward, against the resilience of the front engine mountings, in order to get the cross member to line up with the bolt holes. And that is very difficult to do. A jack doesn't really help because you have to push _forward_.

If, on the other hand, you loosen the lower nuts of the front engine mountings and hoist the engine so as to take the weight off the mountings (it's now dangling like a pendulum), you can easily push the engine/gearbox assembly forward. The engine mountings can now slide along the slotted holes in the mounting supports and you no longer have to battle against the resilience of the engine mountings.

Does that make sense?

I don't understand your problem with the gearbox dropping. If the gearbox cross member has been removed you obviously need something to hold up the gearbox. Use a jack. If the gearbox is too low just jack it up a little higher.

-5. Ouch! I have difficulty in coping with less than +10.