R26 transmission cover removal

Begonnen von Tiago, 21 Juni 2019, 22:09:59

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Tiago

Hello guys,

It has been some time since I last posted here, from past issues with the R27 which you guys helped a lot.

I am now fully restoring a R26 that was badly neglected but apparently running (until I went to see it :p). So I am inspecting everything and starting with the engine and transmission.

This is my first time dismantling the transmission, I am following instructions from the famous Barrington Motor Works manual but even so I am having difficulties removing the cover which needs to be replaced as well, I can only open the gap a few millimeters ( see photos).

I am assuming that the kickstart will come off with the cover and that the output shaft bearing is not moving with the cover (I tap it lightly). And yes, I am heating the cover (with a heat gun).

Can anyone point me in the correct direction from here? What am I missing?

Thank you for your support :)

Sent from my SM-G950F using Tapatalk


Tiago


bwprice100

Hi Toago

I would remove the kick start lever first before removing the cover then it is just heat but if a previous mechanic nay have used loctite a good heating will be needed.

Brian

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Herculestom

Hi Tiago,

my recommendation would be to heat the whole gear box properly and evenly up to about 120 degrees C. Sorry to say, but mama's kitchen oven will be ideal to do that.

If you have a closer look at the gear box, you'll find two or three elevated areas on the cover. The one I can see just above the drain plug. They have been placed there for a reason. With a warmed up gear box and plastic hammer (a normal steel hammer is a no-go!) you'll be able to get the cover off the box. Important to work slowly around the box and to make use of these elevated areas.

For the assembly at a later stage the kick start segment as well as the kick starter will have to be mounted in the cover. Otherwise you'll not be able to turn the segment to the mounting position. Cover to be heated up. Around 100 degrees will do.

Good luck!
Tom
umuntu ngumuntu ngabantu

rolf

try to turn the kickstarter a little more or less....you can feel if it is going free by towing a little bit the cover meanwhile

Tiago

Thanks guys, the good advices are in the details :)

I am searching for a big enough 2nd hand oven to heat this baby up and not get myself in trouble with my wife if I use the one in our kitchen...

Will give some feedback afterwards!

4Taktix

#5
Hi Tiago,
you can also use a low budget solution: put a big flower-pot (terracotta/ceramic) with a drain-hole in the bottom on 2 wood strips.
Place the gearbox (or whatever is desired and fits) into it. Make a wooden lid with a sloped hole near the brim and put the nozzle of a heat gun in it and run it.
The sloped "intake" at the brim makes the hot airflow rotate downwards, and heats up the inside evenly, there it can pass off though the bottom hole.
mark a spot on the outside of the pot, to measure temperature with an IR-temp-gun from time to time. ( DIY-store )
I Did so a few days ago to take my rear-drive apart, works excellent for nearly no extra money.
20 minutes for 130 °Celsius. Depending of what the heatgun is capable of. (watts)
I attached a little sketch to make it clear.
By the way: Whilst you're inside the DIY, also look for insulated or thick gloves  ;) :D

Regards,
Sascha
Think outside the box !

grahamjb

#6
The Gearbox cover is being held in place by the gear shown in the attached photo because the roller bearing hits the gear when you try and remove the  cover.

You have to drift out the shaft that goes through the roller bearing as you lift off the cover - in other words heat up the cover and lift it up as far as you can and then drive out the shaft as you pull on the cover.

There are some more photos on page 5 of my build (R26 restoration by new member from Australia) that may be of assistance.

Cheers from Western Australia

Tiago

Zitat von: grahamjb am 25 Juni 2019, 15:01:54
The Gearbox cover is being held in place by the gear shown in the attached photo because the roller bearing hits the gear when you try and remove the  cover.

You have to drift out the shaft that goes through the roller bearing as you lift off the cover - in other words heat up the cover and lift it up as far as you can and then drive out the shaft as you pull on the cover.

There are some more photos on page 5 of my build (R26 restoration by new member from Australia) that may be of assistance.

Cheers from Western Australia
Hi guys,

Back from my holidays and wrenching again!
Thank you Sasha @4taktix for that comprehensive home oven instructions! But I ended buying a cheap oven instead.

And thank you Graham for your valuable advice, indeed I agree that it is the rear geared part of the input shaft that is not moving and letting go of the bearing that is in the cover...

I already did several oven cycles and the best I could free the cover is about half a centimeter as you can see in the photos. I am really unsure where to hit on that geared shaft so it gets freed from the bearing, I already did that with a brass drift very lightly on the gear but I am afraid to break a tooth.
I am attaching photos of what I can see from the outside, if you guys can guide me it would be great, this is really getting exhausting (2nd night on this).

Thanks again! Cheers!

PS - I cannot see any of your photos with Tapatalk, is this a general issue?

Krottenkopp

Did you press down the kickstarter lever while trying to open the gearbox?
If not it won't work.




Gruß Heiko/2
Gruß Heiko/2

Tiago

Zitat von: Krottenkopp am 09 August 2019, 23:26:23
Did you press down the kickstarter lever while trying to open the gearbox?
If not it won't work.




Gruß Heiko/2
Yes, I did it while opening this bit and it is not blocking anymore. The only thing that apparently is not loosening is that rear of the input shaft in the bearing that is in the cover.

grahamjb

You don't need an oven, you are heating up the gearbox sufficiently as it is coming apart as shown in the photos.

What you have to do is pull on the cover as you drift out the shaft from the bearing that is causing you the problem.
The bearing will stay on the cover because it can't be removed due to the gear being in the way.

Use a piece of brass to drift the shaft out of the bearing so that you do not damage the shaft or bearing. You have to hit it hard to get it to move so hit it nice and hard.

Cheers from Australia

Tiago

Hello again my friends,

Finally got some time to try out your inputs, and the cover is off!
Definitely, I was doing 2 things wrong to get the cover freed from the input shaft:
1) at the point where the cover has already been lifted a bit, I should not have kept heating the whole transmission, just the cover part where the bearing of the input shaft is (did this with a MAPP torch to 100°C)
2) I was not hitting the back of the input shaft adequately, with the dirt deposits masking the shaft, I was afraid to hit the bearing but after thorough cleaning I could identify the shaft looking from the top of the cover, hit it with a bronze rod a couple of time, and the cover was free!

Thanks for all the inputs!

Tiago

Hello guys, I am finally in the final stages with all the renewed shafts and new bearings installed and have now measured the gaps from the shaft bearings to the gearbox cover.

In particular, the gap from the input shaft bearing to case cover recess that I have measured (not including the Bearing Cover ring) is 4.33mm, which means that I will need shims+bearing cover ring for 4.23mm (0.1mm end play).

My question to all restorers here is, I find this value (4.33mm) too high, is this normal for the input shaft? If it is normal, which thickness shims should I use??

All the help is appreciated, as usual

Cheers!

bwprice100

Hi Tiago

I would say that is too high, have you put the cap washer on the end of the input shaft?

https://photos.app.goo.gl/iLQdiAeTjEyotkoE7

Brian

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Kees

I don't know how you meassured, but did you recognise that the outer edge of the cover has a different depth then the bearing pockets in the cover? That's a mistake I made the first time around, but it is too long ago to remember the exact values.

Tiago

#15
Hi Brian,
Indeed, the 4.33mm value is without that cap washer (I referred to it as the Bearing Cover Ring :p), which is missing (can't say if I lost it or it was missing originally!). I need to order a new one with the correct shims.

I have read somewhere that the cap washer adds about 1mm of height? Can anyone confirm? So still missing the other 3.33mm...

Thanks :)

Tiago

Zitat von: Kees am 23 April 2020, 21:09:20
I don't know how you meassured, but did you recognise that the outer edge of the cover has a different depth then the bearing pockets in the cover? That's a mistake I made the first time around, but it is too long ago to remember the exact values.
If you mean that I used a straight edge  and then down to the bearing recesses, yes, I am attaching a photo! I think I measured everything correctly, the other bearings have around 0.2mm of play.

Thanks :)

Kees

Yes that's correct, taking into account this difference. Now also don't make miscalculations with all those pluses and minuses.

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