gearbox crossmenber attachment

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minijojo
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gearbox crossmenber attachment

Post by minijojo »

i am trying to change my gearbox from a 948 to a 1098 one.
I got all parts i need for the 948 engine installed in my Minor to get the 1098 gearbox fitted
Now my problem
2 of the bolts, holding the gearbox crossmember on the chassis leg turn around. So i am not able to remove the crossmember. I have the gaerbox tunnel cover removed but can not see how the bolts are attached in the chassis leg. On the driver side it seams to be under the brakes master cylinder, on the other side i can see nothing inside the cassis leg.
Any tips to solve this problem?
regards
Joachim
philthehill
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Re: gearbox crossmenber attachment

Post by philthehill »

The gearbox cross member securing nuts are held captive and stopped from rotating by cages inside and on the side of the chassis leg.

One of two things can have happened:
-
1. The bolt is seized in the captive nut and when turning the bolt the seized nut has deformed the cage that holds the nut.

2. The cage holding the nut has rotted away and therefore does not hold the nut stationary.

Both of the above are common problems with the Minor gearbox cross member.

I always recommend that the cross member mounting bolts/screws should be removed and the threads cleaned up with a tap and refitted coated in Copperease grease even if the cross member is not required to be removed - because one day the cross member will be required to be removed and the above problems may encountered - better to be prepared than not.

Unfortunately if the captive nuts/cage below the master cylinder are turning to gain access to the nuts/cage the master cylinder will need to be removed if the job is to be done properly in that new cages and nuts are to be fitted.

http://www.moss-europe.co.uk/catalogsea ... q=nut+cage

biomed32uk
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Re: gearbox crossmenber attachment

Post by biomed32uk »

I have just done the same job, I knew they were damaged and had been replaced with ordinary nuts, making removal of the gearbox crossmember 3 x more awkward should I need to, due to the OS being under the master cylinder. While the master cylinder was out it made sense to sort them out. Only one had had a pile of weld heaped up around it, and that was on the near side.

These are the ones under the MC, one was OK so I left it alone on this side, ESM do the nuts and cages, 5/16 BSF.

Not the easiest of places to weld, worst bit is getting the MC out while wondering why the hell someone couldn't be bothered to do the job properly for the sake of few cage nuts and 30 seconds welding, and then bodging any old bolt in that sort of fits.

Image
biomed32uk
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Re: gearbox crossmenber attachment

Post by biomed32uk »

And this is the nearside, just started, had to use a die grinder to grind the bodge of weld out, tapped it back flat from underneath...

Image

Finished and filled up with cavity wax.....

Image
minijojo
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Re: gearbox crossmenber attachment

Post by minijojo »

thank you all for your answers and great photos. Now i know how it should look like
i first thought of some kind of caged nuts. I wonder that i do not see anything in the nearside chassis leg except a bit of rust
chassis_leg.jpg
chassis_leg.jpg (190.76 KiB) Viewed 3854 times
I guess there are a few things to do before replacing the gearbox
I was thinking about placing a thicker sheet metal with the captive nuts welded on in just to give the old chassis lag a little more stability before thinking of an replacement of it
thanks again and a happy weekend
kennatt
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Re: gearbox crossmenber attachment

Post by kennatt »

looks like its had a length of metal laid on top of the leg from inside the car :o
les
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Re: gearbox crossmenber attachment

Post by les »

As mentioned, a common problem. One answer is to use a piece of steel plate the width of the chassis leg and long enough to cover the holes plus a bit more x 5/16'' thick. Holes drilled and tapped 5/16 bsf, at the appropriate spacing, soak in waxoyl or similar, then put in place. The plate can't turn as captivated by the chassis sides.

biomed32uk
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Re: gearbox crossmenber attachment

Post by biomed32uk »

I was thinking about a piece of plate across the whole leg, and welding a couple of fingers in the leg to stop it escaping.

Don't know why but decided to put cage nuts back, I've certainly sorted some poor workmanship out on my car

What's interesting is there are no holes I can see, almost like the bolts on that side were for effect only, with the screws through the floor cover taking the weight on that side. What were or what are the bolts screwed into.

When you have sorted a repair out you need to be filling that leg with some wax or something to prolong its life.
minijojo
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Re: gearbox crossmenber attachment

Post by minijojo »

thanks again for your posts
What's interesting is there are no holes I can see, almost like the bolts on that side were for effect only
thats what i am wondering about too.
But the crossmember is only hold by the 4 screws (in my case no screws, looks more like bolts with nuts). If it was fake only, it would crash down....
when it stops raining i will go on and remove the MC first to see how it looks on the driver side. Thats where both bolts turn round when i try to loose the nuts. The chassis leg on the driver side looks much better, not so much rust as in the nearside one.
I will try to do it the way as already described: place a plate in the chassis leg, drill two holes, put in two screws in the holes, weld them to the plate and fix the crossmember with nuts from the underside.
And yes, i will waxoil it before fitting the gearbox tunnel
Thank you all for your tips, that are things i don't find in any manual and that is what i like this forum for.
biomed32uk
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Re: gearbox crossmenber attachment

Post by biomed32uk »

The crossmember is held by two long screws each side from the top, the tunnel cover screws, and two 5/16 BSF screws underneath at each side.

So if the bolts underneath are missing as long as the two at the top inside the car are there it won't fall out but its not good.

What is suggested is to get a piece of thick plate, the width of the leg inside, chamfer the edges where it runs along the inside of the leg, mark the holes and drill/tap them them 5/15 BSF. So you still screw bolts in from underneath.

I suppose a piece of plate, with bolts through it and then nuts underneath the car will work equally well. If I were doing that I would get some studing, countersink the hole in the plate, put the stud in and fill it with weld.

First job, extraction of the master cylinder, hopefully someone has put the bolts in the other way round, nuts on the torsion bar side.

Good luck with sorting out, you know where you are aiming now.
philthehill
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Re: gearbox crossmenber attachment

Post by philthehill »

If the master cylinder securing bolts are inserted from the centre of the car care must be taken to ensure that the end of the bolt is well away from the torsion bar because if not the end of the bolt can score the torsion bar and create a weak spot.
It should be noted that the torsion bar is not always straight when operating and slight deflection can and does take place along its length - so again most important to ensure adequate clearance between end of bolt and torsion bar.

les
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Re: gearbox crossmenber attachment

Post by les »

Yes important point I missed earlier, chamfering the edges of the plate.

minijojo
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Re: gearbox crossmenber attachment

Post by minijojo »

a little update. Removed the front with radiator. Then removed engine with smooth case gearbox with a motor crane without removing the gearbox crossmember. Went out smooth. Fixed the 1098 gearbox to the engine and tried to install both with the gearbox crossmember installed. No change. Gave up in the evening.
Next day, all gearbox crossmember screws solved. I found out that someone did a quick and dirty job before. Only two M8 (metric) screws are used holding the crossmember to the cassis leg. I was able to solve them by fixing the head of the screw with a locking pliers. Next step is building a plate as discussed before
will keep you up to date
minijojo
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Re: gearbox crossmenber attachment

Post by minijojo »

next steps....
did it the "quick and dirty job" way. But one new chassis leg is already lying in the cellar.
So all should go on smoothly......., i thought
i got a new problem with the 1098 gearbox i wanted to install. First the screws for the rear mounts on the crossmember were installed in the wrong size. The original i ordered for security reason don´t fit any more. Second is the mounting plate of the gearbox steady wire. The 3 screws were „screwed“ a bit in the holes when i got the gearbox, but i could pull them out without tuning them. They are the same thread size as installed in the 948 gearbox but are about 5mm longer. No change to fix them any more. I had not tryed the screws for the clutch relay shaft fixing to the gearbox side.
Is this only a continental problem because some screws are changed into metric size without thinking about the thread in the hole?
I think, yes, bought this car in the Netherlands
Or is it a problem that people lost the feeling how to fasten a screw into an aluminium housing?
I think, yes too.
Now i am thinking about how to proceed.....
Does anyone have a used 1098 gearbox without thread problems in the main mounting holes? offers and tips welcome
philthehill
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Re: gearbox crossmenber attachment

Post by philthehill »

Regarding the three screws for the steady cable into the rear of the gearbox.
Increase the size to 5/16" UNC and Loctite the bolts in place.
The tapping drill required is 6.6mm. As you are tapping alloy a 2nd cut 5/16" UNC tap should suffice. Ensure that you do not drill any deeper than the original depth of hole.
Fit the longest bolt you can without the bolt bottoming in the hole.
BMC fitted the steady cable as an after thought and did not think to increase the size of the bolts from 1/4" UNF to 5/16" UNC.
The stripping of the threads is a common problem and easy to overcome.
You will need to increase the ID size of the three holes in the steady cable front bracket to 5/16" to accommodate the increase size of the bolts.
There are not and should not be any metric threads on a Minor.
All are either Whitworth, British Standard Fine, British Standard Pipe, Unified National Special and Unified National Fine.

The bolts in the side of the gearbox supporting the clutch relay shaft are and should be 1/4" UNF.

minijojo
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Re: gearbox crossmenber attachment

Post by minijojo »

thanks for your tips
will try to get the suitable thread taps and screws.
I agree with you that there should not be metric threads. And no one should fit wrong sized screws.
I have no problem with metric screw and nut fixings as a replacement
biomed32uk
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Re: gearbox crossmenber attachment

Post by biomed32uk »

I will second Phils advice about tapping the three steady wire bracket holes to 5/16, on his advice I did this to mine, and while the gearbox is out is an ideal time.

I have had to sort out all manner of bodged and mangled threads, metric screws in unf/unc/bsf nuts and fasteners. Very clearly done by someone who no idea or cared. anything would do and did !.
minijojo
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Re: gearbox crossmenber attachment

Post by minijojo »

it´s done.
the used 1098 gearbox is in and working.
It was a long way. Two month ran by because i only can work with good weather and on weekend. I had all done twice because of an assembly-paler the clips holding the clutch release bearing got damaged on the first test.
All new bolts fitted in the correct size after retapping the holes.
At last i lost the clutch pedal return spring…..
i replaced it with a beak pedal return spring.
One lucky circumstance, i found the clutch pedal return spring when cleaning the ground. It lay under the cardboard box i placed under the car to prevent oil contamination
So now all got an lucky end, I got a working gearbox with a real roller clutch release bearing (got it from Austalia) and a clutch mechanism from Declan. I guess, a perfect combination.
Thanks to all of you for your tips and hints to get this project come to a good end
regards
Joachim
philthehill
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Re: gearbox crossmenber attachment

Post by philthehill »

minijojo
Can you please post the link for the roller release bearing.
Phil

minijojo
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Re: gearbox crossmenber attachment

Post by minijojo »

Hello Phil
here it is......
http://www.spriteparts.com.au/shop/performance.html
look for roller clutch bearing.
Best is, you email Colin, because of the different types
there is an auction on ebay,de
http://www.ebay.de/itm/181896540574
Joachim
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