hi i am new to renlist and need some help. i have a 82 928 euro 3 speed auto that shifts fine from 1-2 but have no 2-3. have replaced all vac lines from manifold down and tested modulator with mighty vac. modulator holds vac so assume that it is working fine-also have changed filter and replaced all fluid. thought that linkage might be out of adjustment , so i tried bumping selector forward while driving and it just goes to neutral. help!!!

 

Try a Trans-Medic type tranny cleaner in the fluid - one that is intended to be added to fluid rather than used as a flush. I lost 1st gear downshifts and a fluid change fixed it for a week. Adding Trans-Medic fixed it again for several months. One more change and Trans-Medic addition, and it has been fine for 2 years. My conclusion was I had a stuck 1-2 shift valve in the valve body that eventually was cleaned up.

Anyway, I think a stuck 2-3 shift valve is a good possibility. You may need to have the valve body refurbished to fix it however. Steve Cattaneo can provide that service.

 

thanks bill will give that a try and let you know the results

 

Did you save the old filter, if so open it up and check for any clutch debris, was the pan clean, any brunt fluid smell, the 3speed valve bodies, A22, 722.0 and 722.1 have steel check ball which hammer the valve bodies. It could be a bad VB. if the transmission is not burnt.

Bill,
Your transmission diagnostic skills are impressive.

 

Uh, I wouldn't know a valve body if it hit me in the face. I do know there is a 2-3 shift valve in there, and with 2-3 gone, it's the kind of thing that I can't avoid suggesting. The Trans-Medic (or Trans-Kleen, whatever) did work for me, although it required two treatments. I no longer use it, and he tranny has been fine since the last fuild/filter change (every 30k miles!). I'm always glad you see these threads and bring up the other possibilities. If the steel ***** have beat up the valve or the clutch has worn, then Trans-Medic is not likely to help, but it's worth a try.

 

no, fluid smelled and looked good, and pan was very clean-quick wipe with paper towel cleaned it out- no fibers or metal shavings of any sort. i did fail to mention earlier that this car was pulled out of a fence row a few years back- got it for a steal of 2k even though i had to rebuild motor and replace fuel injection system- i think i got a good buy. last time car was inspected was in 97- so i hope that the cleaning my do the trick- about to go out to the shop and give it a go and then run the back roads for a while to get things moving- tnx again guys-oh bill love the burn out video

 

just an update- changed fluid and added tranfusion and drove as DD all week with no change as of yet- am going to change fluid and give another shoy of transfusion this week to see if that will finally turn it lose- no fun driving at 60mph at 3k- will keep you posted

 

Hi

Umm...I know this is going to sound silly.....but are you SURE you have lost 2/3 shift ??

If its pulling away in second (as it should) ...then what you think of as 1/2 shift is actually 2/3....so you havent lost it.....if you see what I mean ... ??
Easy to know..... on my 4 speed auto 2/3 shift is at 77 mph .....and 3/4 shift is at 117 mph.....both under wide open throttle conditions....1/2 shift is at 44 mph by the way.

OOps just noticed yours is a 3 SPEED AUTO...

OK...your 2/3 shift is at around 110 to 120 mph under WOT ....from memory...

All the best Brett

PORSCHE 928 S2 AUTO V8 4.7 LTR 1986 IRIS METALLIC BLUE WITH X-PIPES ,RMB ,PROMAX CHIPS, KICKDOWN SWITCH, K&N, WIZARDS OF NOS - NITROUS KIT 150 HP JETTING - 505 BHP / 500 FT LBS TORQUE
PCGB UK 928 FORUM MODERATOR - Email managingdirector@pchealthcare.co.uk

 

Hi Again

Just reread exactly what you said....and I dont quite understand what you are saying????

ARE you saying you cannot get top gear (3) at all ???

If thats true...you cannot get past 120 mph.....it would be impossible in second gear???

Could you clarify speeds in gears ...and maximum speed you can reach???

All the best Brett

PORSCHE 928 S2 AUTO V8 4.7 LTR 1986 IRIS METALLIC BLUE WITH X-PIPES ,RMB ,PROMAX CHIPS, KICKDOWN SWITCH, K&N, WIZARDS OF NOS - NITROUS KIT 150 HP JETTING - 505 BHP / 500 FT LBS TORQUE
PCGB UK 928 FORUM MODERATOR - Email managingdirector@pchealthcare.co.uk

 

hey sorry to be late getting back to you guys- all the help i can get the better. my max speed is 110mph so pretty darn shure that i don't have third, also have tried to manually shift through the gears to see what happens- and shure enough only getting two of the three- have heard of two dead-(cry- cry) sharks in the area and am going to try and track them down this weekend- anyone know if a 4 speed will fit? have a line on one of those also. thnks again-oh one more thing the last two times that i have chnged the fluid i seem to be getting a lot more gunk out, so will also be changing fluid out again and again and- untill clear

 

Your transmission starts in 1st gear in D from a stop, the next shift is 2ND then 3rd ,if you feel two shifts you have third gear.

 

only feel 1 shift at about 25mph under normall driving conditions-crusing speed of 60mph while turning about 3k.

 

Hi

If you can only get to 110 mph..then YES you have lost third....

All the best Brett

PORSCHE 928 S2 AUTO V8 4.7 LTR 1986 IRIS METALLIC BLUE WITH X-PIPES ,RMB ,PROMAX CHIPS, KICKDOWN SWITCH, K&N, WIZARDS OF NOS - NITROUS KIT 150 HP JETTING - 505 BHP / 500 FT LBS TORQUE
PCGB UK 928 FORUM MODERATOR - Email managingdirector@pchealthcare.co.uk