Fixing 915 of Euro-spec MY80 SC

[WP0ZZZ]

This morning I test-drove an Euro MY80 SC and the gearbox felt very far from perfect. I would like to share the symptoms with you and I would be very grateful to know your thoughts on how hard it would be to fix them.

1. Lever moves freely right and left from neutral. No "springiness" as one would expect in a manual gearbox.

2. Moving the lever into first gear I didn't feel any mechanical feedback to tell me that I was in gear. In other words, the lever slides into position and stays there but there is no tiny vibration in the lever like in most gearboxes to suggest that the lever has moved through the point at which the gear is engaged. Hard to explain the feeling. Hope that you kind of understand what I mean.

3. Second gear engaged pretty well both upshifting and downshifting. Third gear was a bit of a pain in the ass. Hard to engage when upshifting.

[Flat6pac]

Sounds like bushings and shifter alignment. Maybe the swivel bushings in the back seat access are gone, it is almost 40years old.
Bruce

[Peter Zimmermann]

WPO; have a 915 expert, if you can find one, drive the car. 915s are a different animal, and they really can't compare to other manual transmissions that you might have driven in the past.

3rd gear upshift is a concern, how many revs were you using when you encountered difficulty?

[WP0ZZZ]

Originally Posted by Flat6pac

Sounds like bushings and shifter alignment. Maybe the swivel bushings in the back seat access are gone

Would this cause the lack of lateral self-centering around neutral?

Originally Posted by Peter Zimmermann

WPO; have a 915 expert, if you can find one, drive the car. 915s are a different animal, and they really can't compare to other manual transmissions that you might have driven in the past.

3rd gear upshift is a concern, how many revs were you using when you encountered difficulty?

Unfortunately I don't know any 915 specialist in my area.

I was doing the upshift to third at low revs, around 2-3k.

[darrin]

self-centering around neutral sounds normal -- my properly set up 915 has freeplay with no centering between 1st/2nd and 3rd/4th) but has a spring resistance between 3rd/4th and 5th/reverse. So, I slap left to find 1st and second, push right (but not hard against spring resistance) to find 3rd/4th and then keep pushing right through spring resistance for 5th/reverse.

Usual 915 issues include a) worn/dead 1st gear synchros, b) worn 2d gear synchros that will crunch a bit on 1st to 2d shifts.

[Bill Douglas]

Sounds quite good to me.

I'd renew the coupler, put in sport engine and transmission mounts and change the gearbox oil.

[Flat6pac]

Darrin

Having spring pressure to the left in the shifter, sounds like your shifter is a earlier shifter.
You’re suposed to have spring pressure to the right for fifth and reverse.
Bruce

[darrin]

Originally Posted by Flat6pac

Darrin

Having spring pressure to the left in the shifter, sounds like your shifter is a earlier shifter.
You’re suposed to have spring pressure to the right for fifth and reverse.
Bruce

Bruce -- I think we're saying the same thing (but you said it more eloquently) -- push through spring pressure to the right when engaging 5th/reverse, no spring pressure between/among the first 4 gears.

[Matt Monson]

Originally Posted by WP0ZZZ

I was doing the upshift to third at low revs, around 2-3k.

Yeah, you don't want to do that. Engine doesn't even make peak torque until over 4000. Next time you drive one make sure that both the 1-2 shift and 2-3 shift are at or above 3500. There's no sound argument to shifting any lower.

[WP0ZZZ]

Originally Posted by darrin

push through spring pressure to the right when engaging 5th/reverse, no spring pressure between/among the first 4 gears.

Cool. So that clarifies that the behaviour I observed was to be expected.

Originally Posted by Matt Monson

Yeah, you don't want to do that. Engine doesn't even make peak torque until over 4000. Next time you drive one make sure that both the 1-2 shift and 2-3 shift are at or above 3500. There's no sound argument to shifting any lower.

If I end up buying the car I'll make sure that I don't change below 6000

[Matt Monson]

[WP0ZZZ]

Originally Posted by WP0ZZZ

2. Moving the lever into first gear I didn't feel any mechanical feedback to tell me that I was in gear. In other words, the lever slides into position and stays there but there is no tiny vibration in the lever like in most gearboxes to suggest that the lever has moved through the point at which the gear is engaged. Hard to explain the feeling. Hope that you kind of understand what I mean.

I'm still wondering if the "problem" number 2 is something to be expected in a 915 gearbox or if it's due to an issue. Any ideas?

[Josh D]

Originally Posted by WP0ZZZ

I'm still wondering if the "problem" number 2 is something to be expected in a 915 gearbox or if it's due to an issue. Any ideas?

The coupler bushings and the cup bushing in the shift rod below the shifter would need to be inspected and found in good shape before problems with the transmission are assumed. I understand that makes purchasing the car more of a risk, but these bushings are known issues with shifting feel and problems related to these cars.