280se (M110) transmission in 617a?

[cho]

hi guys

I know it is bolt in option,but I m not sure about shifting points
it is 1984 automatic 722.307 and it should replace 722.303

do you know anyone done it?

my .303 is close to death and no other diesel automatics available here...

cheers

.

[t walgamuth]

I did the opposite, a diesel tranny into a 280e. It works fine but the shift points are too low. In your case they will be too high. I suppose it won't be a problem as it should shift long before the rev limiter kicks in unless you hold the gas pedal to the floor...and if you do that it will hit the rev limiter and when the engine slows down it should shift....? Not sure but if you need a tranny it should work, just not as seamlessly as the factory one did.

[cho]

thanks T.

unfortunately I need one as my 4th gear is broken,...If I understand you correctly the 280 tranny will need higher rpm's to shift rather than .303?

would it make some noise issues on highway?


.

[Dr. Sternschnuppe]

The 722.303's valve box & vacuum box will fit and work correctly on the 722.307.
And then check modulating pressure after changing of the vacuum box & vacuum box.

[cho]

.
Grüezi Dr. Sternschnuppe

I m not sure what you think by changing vacuum and valve box....
My plan was just to swap complete .307 in place of .303
and if possible not using any parts of my old and tired .303

cheers

[Dr. Sternschnuppe]

Originally Posted by cho

.
Grüezi Dr. Sternschnuppe

I m not sure what you think by changing vacuum and valve box....
My plan was just to swap complete .307 in place of .303
and if possible not using any parts of my old and tired .303

cheers

OK, i understand you.

But, then change only modulator (vacuum box) - for smooth shifting.

[Stretch]

I'm not sure if it is 100% complete any more (after moving house and putting loads of stuff in storage) but I did have a 722.303 valve body in bits (same as the .315) - the next time I'm at my storage unit I'll see if it is still about - it could have gone to the tip with the rest of the stuff though...

...long story short if I have it and you want it I'll send it off to you if that'll help you out...

[cho]

Originally Posted by Stretch

I'm not sure if it is 100% complete any more (after moving house and putting loads of stuff in storage) but I did have a 722.303 valve body in bits (same as the .315) - the next time I'm at my storage unit I'll see if it is still about - it could have gone to the tip with the rest of the stuff though...

...long story short if I have it and you want it I'll send it off to you if that'll help you out...

thanks T.

...that very generous! but at the time I don't have enough...khm... courage for such en devour I will settle with just replacing the .303 with .307

cheers

.

[Stretch]

Well keep us posted - if it all goes tits up at least you know of someone who has a valve body for a .303

Note also the governor is different for the .303 so I guess that would have to match.

Don't throw the old transmission in the bin until you know your swap is good.

[cho]

Originally Posted by Stretch

Note also the governor is different for the .303 so I guess that would have to match.

now I m officially scared....again
swapping governor does not seem to be easy task.....

is it like...it's so different so it can to be plunged in at all
or like it can be plunged but some performance will be lost?

cheers

.

[Stretch]

Originally Posted by cho

now I m officially scared....again
swapping governor does not seem to be easy task.....

is it like...it's so different so it can to be plunged in at all
or like it can be plunged but some performance will be lost?

cheers

.

The governor and the valve body are type matched - so if you have a 722.303 valve body ideally you need the matching governor (both the governors and the valve bodies in the 722.303 or the 722.315 - "diesel" transmissions are the same - but different governors and valve bodies are used for "petrol" transmissions)

I wouldn't go swapping a "diesel" valve body with a "petrol" one - that would make Bowden cable and vacuum adjustments pretty weird if you leave the "petrol" governor in there.

If you want to mate a "petrol" transmission to a diesel engine I think you are best trying to adjust the transmission (if needed) to be as close as possible to the petrol specifications listed in the FSM and see how you go.

(do you need FSM data?)

[cho]

.

yes...my plan was more like "lego" based

unbolt my current .303 and bolt on .307... test drive...

if some minor shifting point weirdness arise...ok..dont touch anything

severe shifting points issues...try to adjust...

if not successful...send a few secret service agents cross Europe
for 5 spd 717.400 quest...

/

[Stretch]

Originally Posted by cho

.

...
if not successful...send a few secret service agents cross Europe
for 5 spd 717.400 quest...

/

Might be able to help there too (but keep that hush hush)

[clacker]

I would worry about downshifts past the diesel redline, as in passing or required power the trans might downshift into an rpm range not suited for a diesel, maybe the Bowden cable adjustment could help avoid that (slack). There should be a way to adjust pressures so it won't shift too, but that is not my area of knowledge! I can ask though if it is needed.

[t walgamuth]

Originally Posted by clacker

I would worry about downshifts past the diesel redline, as in passing or required power the trans might downshift into an rpm range not suited for a diesel, maybe the Bowden cable adjustment could help avoid that (slack). There should be a way to adjust pressures so it won't shift too, but that is not my area of knowledge! I can ask though if it is needed.

The diesel engine is governed so if you push the pedal down to pass and it downshifts at too high an rpm it will not provide fuel to run.