The New And Improved Unofficial R65 Forum V2

Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: fbenach on November 25, 2012, 08:03:52 PM

Title: Transmission problem!!
Post by: fbenach on November 25, 2012, 08:03:52 PM
Hey guys, me again...
Today I went for a 200km ride, and in the way back, in the last 30kms my transmission started to sound awful, like there was something spinning and cranking... no particular vibrations nor lack of power...

What I notice when I get home was that in neutral position and the clutch applied, the sound goes away as well as 2nd gear... but still, if I´m in neutral and start releasing the clutch, the bike runs like it was in gear!!!

What´s going on?? could it be my gears are not synchronized somehow???
We just finished a major job on the engine 2 weeks ago, where we replaced the crank... but, the failure started 300kms after the job...

I´m lost!!! any ideas???
Thanks in advance!!!

Title: Re: Transmission problem!!
Post by: Bob_Roller on November 25, 2012, 08:37:58 PM
Possibly a clutch throw out bearing at the back of the transmission .
Title: Re: Transmission problem!!
Post by: montmil on November 25, 2012, 09:25:44 PM
Quote
Possibly a clutch throw out bearing at the back of the transmission .

Not an uncommon issue. Fortunately, a fairly easy repair job and it won't burn down your wallet.
Title: Re: Transmission problem!!
Post by: fbenach on November 25, 2012, 09:53:52 PM
Your words are like music to my ears!!!
Thanks guys!!
Title: Re: Transmission problem!!
Post by: montmil on November 26, 2012, 06:44:15 AM
Quote
Your words are like music to my ears!!! Thanks guys!!

And worth exactly what you paid for 'em! ;D
Title: Re: Transmission problem!!
Post by: Bob_Roller on November 26, 2012, 10:30:02 AM
Well, that's a starting point !!!!!!!
Title: Re: Transmission problem!!
Post by: tvrla on November 26, 2012, 03:32:16 PM
If you haven't pulled the drain plug and checked out the magnet - now's an appropriate time. Anything more than soft fuzz is someting to worry about!

I wonder if there wasn't enough free play in the throwout system and it got over-worked?
Title: Re: Transmission problem!!
Post by: fbenach on November 26, 2012, 05:30:10 PM
Quote
If you haven't pulled the drain plug and checked out the magnet - now's an appropriate time. Anything more than soft fuzz is someting to worry about!

I wonder if there wasn't enough free play in the throwout system and it got over-worked?

Magnet? Drain?? where??
Well I talked to the guys on the shop... the gear box was supposely untouched during the crank job... and my mechanic says it should be a bearing as Bob suggests...

Where should I be looking now?
Thanks!!
Title: Re: Transmission problem!!
Post by: montmil on November 26, 2012, 06:24:40 PM
Transmission drain plug -most all have a magnet at the threaded end.

First check the throw out bearing as Bob suggested. It's right there at the end where the clutch pushrod enters the box. Going into the gear box without knowing for sure if anything has failed is going to cost you several hundred bucks.

That's if nothings wrong!
Title: Re: Transmission problem!!
Post by: fbenach on November 26, 2012, 11:48:23 PM
OK, tomorrow we will check that before opening the whole thing!!

Thank you again!!
Title: Re: Transmission problem!!
Post by: Lucky_Lou on November 27, 2012, 11:08:07 AM
Quote
Hey guys, me again...
What I notice when I get home was that in neutral position and the clutch applied, the sound goes away as well as 2nd gear... but still, if I´m in neutral and start releasing the clutch, the bike runs like it was in gear!!!!!
? Are you saying that the bike is trying to drive in neutral, or just gettin the noise ? is so that may be a sign of a bigger problem
Lou
Title: Re: Transmission problem!!
Post by: fbenach on November 27, 2012, 06:53:24 PM
Well yes, in neutral position, and clutch pressed, there is no noise, but if I release the clutch it starts making the sound and drive... it seems like somehow it is still in gear (1st or 2nd)... we dismantled the gearbox today, I´m waiting for a diagnosis tomorrow...
Let´s see what happens... I´m crossing my fingers for something not that big...
Title: Re: Transmission problem!!
Post by: Dave 2 on November 27, 2012, 09:59:37 PM
Have you checked your clutch Cable?
Title: Re: Transmission problem!!
Post by: fbenach on December 06, 2012, 06:38:12 PM
Well, we finished the job, thankfully it was nothing big, it was the white ring that is mounted on the shifting cam (lock ring??)...
We checked all the gears and they were perfect, though we changed all the bearings just in case...

Thanks for the help guys!!
Title: Re: Transmission problem!!
Post by: tvrla on December 07, 2012, 07:31:03 AM
You left me in mystery on this one??? A picture would definitely help!

I don't recall seeing any white rings in the gearbox. Are you talking about the roller that rides on the shift cam?
Title: Re: Transmission problem!!
Post by: fbenach on December 07, 2012, 07:13:46 PM
I might be calling it the wrong way.... this is an image I got from the net...

The white circle piece had an "oval" shape and was somehow leaving my bike between gears...
Title: Re: Transmission problem!!
Post by: tvrla on December 08, 2012, 12:15:42 AM
Thanks for clearing that up for me! It's what I thought you were describing. It's a roller that indexes the shift cam. If it's not working properly, it might not keep rolling to the valley between peaks - the point where gears are selected.
Title: Re: Transmission problem!!
Post by: fbenach on December 08, 2012, 01:03:32 AM
Well, once again, I learn something new from you my friend!!!

I have another question... while we were doing this job, I talk to a guy that has some disarmed pieces of a 79 R65, I actually ended up buying from him a 31/9 final drive in good shape (I might be changing my crown), a couple of nice Krausers and front/back rims in good shape...

He does have two complete fork sliders and some other stuff...
What really got my attention was the following two items:
1. front/back 18" rims from what we suspect was a R60 of 1971
2. a sealed gearbox with kick starter from who knows what model.

How can you tell what kind of gearbox is this? Is there any code or part number on it that could identify it? I kinda wish it fits my 79 R65, I would love to have a kick starter!!!

Check it out!!!
And again, thanks!!
Title: Re: Transmission problem!!
Post by: georgesgiralt on December 08, 2012, 03:04:38 AM
Hello !
All gearboxes are the same internally (same gears ratio) and same casing. So you could replace a ribbed tranny (5 speeds) by another one PROVIDED that the clutch are/was the same.
The heavy flywheel and the light one give a different input shaft on the gearbox.  So you have to measure the input shaft of the gearbox you plan to buy and check if it correspond to the clutch model you have on your bike.
If I were you, I'll buy the gearbox anyway, rebuild it (new selection springs, bearings and gaskets) adapt the input shaft to my bike if needed then put in place of my original. You will have to strip the input shaft to replace the internal front bearing race. So .....  
Of course for this to be cost effective, you have to buy it at low price...
Title: Re: Transmission problem!!
Post by: Julio A. on December 08, 2012, 09:35:46 AM
The kick start lever looks a different than the one I have on my r65. The one on the picture looks straight while the one on mine has slight bends to clear the shift lever.
Title: Re: Transmission problem!!
Post by: tvrla on December 08, 2012, 08:02:46 PM
The side opposite the kick lever - the one with the splined shaft out the center - has a date code on it. There's also a serial number on it somewhere but I don't recall where that would be. Both of those numbers will help identify the transmission.

I think it might be for the 1981 -> bikes, but not sure. They changed the outside ribbing when they upgraded the internals and the clutch but don't recall what the visual clues are.

If you decide not to get it, let me know - I want it!
Title: Re: Transmission problem!!
Post by: fbenach on December 08, 2012, 08:25:54 PM
Wirespokes, that can be another possibility!! but take in consideration I am in Costa Rica!! the sending costs could be  little high...

Anyways, I am sure is before 1981... the question would be... will it fit somehow in a R65, otherwise, I will probably get it and put it on eBay!!

What do you think?
Title: Re: Transmission problem!!
Post by: tvrla on December 09, 2012, 06:52:20 PM
You're probably right about shipping being prohibitive.  ::)

Check the date stamp - that will tell you a lot. Also, you could measure the length of the exposed input shaft. I may be able to check the lengths of the different versions.

How about putting your location in your profile?
Title: Re: Transmission problem!!
Post by: fbenach on December 09, 2012, 07:04:36 PM
OK, done!!!

I will check the dimensions on the gearbox!!!

here I found this link with some nice info on transmissions... Will read it carefully!!!
http://bmwmotorcycletech.info/transmission.htm

Thanks!!
Title: Re: Transmission problem!!
Post by: fbenach on December 10, 2012, 06:29:47 PM
OK, went out to pick the tranny this evening... it has what appears to be a part number for the housing... 23 11 1 238 806

I searched for it on the MaxBmw site but nothing came up...
My mechanic feels it is compatible with my bike, as long as it seems to use the same clutch system than mine...

Any ideas where to check on this??

Thanks!!
Title: Re: Transmission problem!!
Post by: tvrla on December 11, 2012, 12:01:19 AM
In the photo on the right side there's a circle with writing inside. I can't tell but it might say 82/83, which would be the year of manufacture.

I'm pretty certain this is the generation after yours.
Title: Re: Transmission problem!!
Post by: fbenach on December 11, 2012, 12:30:00 AM
Yup!! I think you are completely right...
I found this on eBay, same numbers on a 84 R65!!!

Well, I´ll have to find someone who could use it!!! ;)

http://www.ebay.com/itm/1984-BMW-R65-S-T-RS-R70-R90-R100-S273-transmission-trans-airhead-/290829200257?pt=Motorcycles_Parts_Accessories&hash=item43b6c56b81&vxp=mtr
Title: Re: Transmission problem!!
Post by: georgesgiralt on December 11, 2012, 12:42:55 AM
Hello !
So as it seems, your gearbox is for a new, light flywheel.
But, as you know, these tranny are the weak spot. So if I where you, I rebuild the extra tranny swapping the input shaft to adapt to my bike/engine and stock it just in case mine broke.
The input shaft has to be stripped in order to change the input bearing inner shaft, and if the tranny has a high mileage, the splines at the clutch coupling could be worn out... so you may need to replace the shaft anyway...
This should keep you occupied for the  winter months...
But it is just me ...
Title: Re: Transmission problem!!
Post by: fbenach on December 11, 2012, 01:11:07 AM
Thanks George, that makes sense!!!

I will have to sit down with the mechanic and see whats the state of this tranny... he has a couple of pre-81 units in the shop, so we will compare...

Thank you for the advice!!
Title: Re: Transmission problem!!
Post by: Bob_W on December 12, 2012, 07:26:25 AM
The input splines are different. Later boxes had more splines. To my early morning and very old eyes, yours appears to be one of these. Also beware the kickers,  while seemingly a good thing are not very reliable on later boxes. Only for emergency use.
Bob
Title: Re: Transmission problem!!
Post by: Bob_W on December 12, 2012, 09:44:00 AM
I stand corrected. The spline area is longer not more splines. Snowbum has all the information you ever wanted to know about transmissions and the variations over the years.
Bob
Title: Re: Transmission problem!!
Post by: tvrla on December 12, 2012, 07:13:44 PM
Yeah, snowbum has all you ever wanted to know, and more!  :)

The early first version boxes had a longer input shaft spline section (14mm), newer ones are 9mm.
Title: Re: Transmission problem!!
Post by: fbenach on December 12, 2012, 09:36:44 PM
Yes... I´m still reading stuff about it...
some guys says that if a rebuild is done on one of the "new" style boxes, it is possible to have them installed on an "old" style engine along with the necessary parts... some jut say is not possible...

The good news is that, along with the reading process and your knowledge, I learn... which is the ultimate goal!!!
Title: Re: Transmission problem!!
Post by: tvrla on December 13, 2012, 10:50:19 PM
It is possible to put the new style guts in an older box, but the new style rear cover will be needed. That, and the newer style clutch and clutch carrier. The old heavy flywheel will have to go.