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HELP!!! Transmission meltdown...

Posted: Sat Jun 16, 2018 9:38 am
by hubskadub
Not sure how this happened, but it did. 4400 original miles on motor, 500 miles on a full rebuild. 1400cc stamped on this 1974 motor and it was full of oil, no leakage.

Anybody have a full transmission set for a 74 or compatible in the US?

Re: HELP!!! Transmission meltdown...

Posted: Sat Jun 16, 2018 12:06 pm
by sportston
Wow, that is one truly buggered set of cogs!

Re: HELP!!! Transmission meltdown...

Posted: Sat Jun 16, 2018 1:00 pm
by Zunspec4
Hello hubskadub,

I saw your post on Facebook too. My comment is that the damage you have unfortunately suffered is typical of oil starvation caused by low oil in the gearbox. As you have "1400cc" crankcases there should be no requirement for the "Oil Dam" modification unless the lower case is not the original. As you know the history of the engine this is unlikely.

That just leaves the possibility that when your mechanic re-filled the gear box he did not measure his 1400cc accurately. Or he used the level plug on the clutch cover as his reference point which is not an accurate way of ensuring the correct amount of oil. The other possibility is that all was OK to start with but the inner crank seals have been passing oil resulting in a low oil condition. When you split the cases did you find both of the oil baffle plates in position, I only spotted one in your photos. The omission of the rear plate could also result in the oil not being deflected over 4th/5th gears.


Cheers Geoff

Re: HELP!!! Transmission meltdown...

Posted: Sun Jun 17, 2018 1:56 pm
by dorT500
All good points made by member Zunspec and I'm getting a vision :| , another possibility. Maybe it's me or just the lighting in the pictures but does it look like there may have not been a continuous bead of sealant applied or it was breached when engine went into service,especially on the wall that separates the transmission from the crank chamber and maybe none applied to critical areas around the oil channel(need a very fine thin layer as not to have excess squeeze into channel) to the center bearing oil port. Type of sealant used? Mating surfaces completely wiped down with acetone or the like before sealant applied? Transmission filled back up with oil and engine started before some sealant that is not even suppose to be used for this purpose had reached its curing time? Upper and lower case bolts torqued to the proper values and in order as per the number stamped in the case near each bolt?

Some do a pressure and vacuum test after installing new inner and outer crankshaft to test if there are any breaches in a cured seal. It's possible you can hear a leak/breach(muffled hissing sound)coming from a pressurized crank chamber by removing the oil fill plug and putting an ear close to the hole.

Obviously, what I'm getting at is that maybe, just maybe, transmission oil was being sucked into the crank chamber maybe by the drop or even just as a mist during those 500 miles you rode.

BTW, were those 500 miles highway or city miles you put on the clock?

Bloody shame about the damage and buying a transmission off ebay can be risky if only that it can be so hard to see any telltale evidence of flaws/damage and the degree of wear on all driven gears and gear wheels even with a lot of pictures.....been there....done that. Best chance of course, if the price is reasonable enough to gamble on is to wait and see one listed as low mileage and taken out of a later model T or GT500.

There is a 4th gear driven listed on ebay....been listed a long time by a 'certain' seller that says it's NOS but at that price and by the picture....I'm just not 100% sure it's NOS...I could be very wrong( I'm slowly putting a spare driveshaft together with NOS gears and wheels) but I'm in no hurry to gamble on it. 'Somewhere down the road', I might wind up buying at least 4th and 5th driven gears from and maybe send a counter shaft to one of the companies below for 4th and 5th counter gears.


You may already know about these companies but just in case you don't....

http://www.novaracing.co.uk/ProductSuzu ... Gears.html" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;"

I don't know for sure if he is still making gears and I can't find a link just now for Moore Engineering but there is reference to both in this thread....
viewtopic.php?p=87359" onclick="window.open(this.href);return false;" onclick=

Again, sorry about that mess and good luck ironing out the issues.

Re: HELP!!! Transmission meltdown...

Posted: Mon Jun 18, 2018 11:32 am
by johnakay
look like they're still on the go................
https://tyldesley.cylex-uk.co.uk/compan ... 24552.html" onclick="window.open(this.href);return false;

Re: HELP!!! Transmission meltdown...

Posted: Mon Jun 18, 2018 9:00 pm
by hubskadub
Zunspec4 wrote:Hello hubskadub,

I saw your post on Facebook too. My comment is that the damage you have unfortunately suffered is typical of oil starvation caused by low oil in the gearbox. As you have "1400cc" crankcases there should be no requirement for the "Oil Dam" modification unless the lower case is not the original. As you know the history of the engine this is unlikely.

That just leaves the possibility that when your mechanic re-filled the gear box he did not measure his 1400cc accurately. Or he used the level plug on the clutch cover as his reference point which is not an accurate way of ensuring the correct amount of oil. The other possibility is that all was OK to start with but the inner crank seals have been passing oil resulting in a low oil condition. When you split the cases did you find both of the oil baffle plates in position, I only spotted one in your photos. The omission of the rear plate could also result in the oil not being deflected over 4th/5th gears.


Cheers Geoff

Can you post a pic of both of the oil dams, front and rear just so I can be sure they are both in there? I only see one on the spec drawing...

Re: HELP!!! Transmission meltdown...

Posted: Mon Jun 18, 2018 9:05 pm
by hubskadub
dorT500 wrote:All good points made by member Zunspec and I'm getting a vision :| , another possibility. Maybe it's me or just the lighting in the pictures but does it look like there may have not been a continuous bead of sealant applied or it was breached when engine went into service,especially on the wall that separates the transmission from the crank chamber and maybe none applied to critical areas around the oil channel(need a very fine thin layer as not to have excess squeeze into channel) to the center bearing oil port. Type of sealant used? Mating surfaces completely wiped down with acetone or the like before sealant applied? Transmission filled back up with oil and engine started before some sealant that is not even suppose to be used for this purpose had reached its curing time? Upper and lower case bolts torqued to the proper values and in order as per the number stamped in the case near each bolt?

Some do a pressure and vacuum test after installing new inner and outer crankshaft to test if there are any breaches in a cured seal. It's possible you can hear a leak/breach(muffled hissing sound)coming from a pressurized crank chamber by removing the oil fill plug and putting an ear close to the hole.

Obviously, what I'm getting at is that maybe, just maybe, transmission oil was being sucked into the crank chamber maybe by the drop or even just as a mist during those 500 miles you rode.

BTW, were those 500 miles highway or city miles you put on the clock?

Bloody shame about the damage and buying a transmission off ebay can be risky if only that it can be so hard to see any telltale evidence of flaws/damage and the degree of wear on all driven gears and gear wheels even with a lot of pictures.....been there....done that. Best chance of course, if the price is reasonable enough to gamble on is to wait and see one listed as low mileage and taken out of a later model T or GT500.

There is a 4th gear driven listed on ebay....been listed a long time by a 'certain' seller that says it's NOS but at that price and by the picture....I'm just not 100% sure it's NOS...I could be very wrong( I'm slowly putting a spare driveshaft together with NOS gears and wheels) but I'm in no hurry to gamble on it. 'Somewhere down the road', I might wind up buying at least 4th and 5th driven gears from and maybe send a counter shaft to one of the companies below for 4th and 5th counter gears.


You may already know about these companies but just in case you don't....

http://www.novaracing.co.uk/ProductSuzu ... Gears.html" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;"

I don't know for sure if he is still making gears and I can't find a link just now for Moore Engineering but there is reference to both in this thread....
viewtopic.php?p=87359" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;" onclick=

Again, sorry about that mess and good luck ironing out the issues.

Wouldn't the bike run like crap if it had a leaky crankcase? It runs very well... I was doing all kinds of riding on it but it failed on a longer highway stint... Not sure of any noises as the exhaust is really loud on mine even though it has stock pipes... Not sure if you are supposed to repack them or what but I admittedly didn't hear anything until it let go.

Found a guy in Indiana that has multiple motors and is tearing into one to get me a tranny. A trusted source from the sounds of folks on the FB group.

Re: HELP!!! Transmission meltdown...

Posted: Tue Jun 19, 2018 6:53 am
by Zunspec4
hubskadub wrote: Can you post a pic of both of the oil dams, front and rear just so I can be sure they are both in there? I only see one on the spec drawing...
Hi Hubskadub.

Here is a photo showing the two "Oil Guides" fitted in the gear box. One secured by 6mm cross headed screws and the 2nd slotting in and over the two small pillars (sorry the plate is a bit rusty but it was the only one I could find amongst my spares). Like you I cannot find the 2nd plate on the parts diagram, but it should be there.
Image

Cheers Geoff

Re: HELP!!! Transmission meltdown...

Posted: Tue Jun 19, 2018 9:18 am
by jabcb
Copy of an old printed parts manual shows the two guides under crankcase: https://www.oldjapanesebikes.com//mraxl ... /index.php

The part #, 24881-15000 & 24829-15000, are shown are available in the NL: http://www.classicsuzukiparts.nl/2strok ... 0/?lang=en

Re: HELP!!! Transmission meltdown...

Posted: Tue Jun 19, 2018 10:01 am
by dorT500
hubskadub wrote:Wouldn't the bike run like crap if it had a leaky crankcase? It runs very well...........Not sure of any noises as the exhaust is really loud on mine even though it has stock pipes... Not sure if you are supposed to repack them..............
Could run good or 'alright' especially if it was just a mist of oil entering the crank chamber but now that you say it was running very well then just drop back to the other possibilities already mentioned because the only other thing I can think of offhand is a slight misalignment between driven gears and counter shaft gears. That is, one or both high gears on the counter shaft shifted in just a tad but it looks like you have the type of counter shaft that has spacers between the gears. Some counter shafts don't have those spacers and I did see a counter shaft once without the spacers where the fifth gear had shifted inwards....ever so slightly....however rare....but it had. Well, I'm getting off into the weeds but bottom line is that picture of the transmission you posted is classic evidence of oil starvation.

About the exhaust baffles....stock exhaust baffles for the T500 did not have packing. On that oil deflector in the lower case, I don't recall if the uppercase splash/drip plate would keep the lower oil deflector plate from dropping out of place if the engine is turned upside down while buttoning it back up but bending the slot tabs..'ears' on it just a tad will create enough tension between them and the slots it slides into to hold it in place fore sure.

Looks like your case has the upper splash/drip plate. At least I can just make out one of the screws that attaches it to the case and just for a little history about that upper plate and oil level.....


Thanks Ian.....
https://www.oldjapanesebikes.com/mraxl_ ... ms/page-71" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;"