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joecitizennn · Joined: 12 Sep 2005 Posts: 2096 Location: no mans land

I recently bought a new synchro ring for third gear on a 1987 Porsche 944 transmmission from Pelican. Part number 016-311-295-m59 is supposed to cover 2-4th gears on this type of transmission. It arrived in just a few days and I immediately noticed that though it is 90% identical to the original it has one small difference. On the original ring there are three tabs or fingers that are positioned above the synchro lock grooves. These fingers are missing on the new synchro ring. I double checked the part number and application and decided surely it must be ok and re-assembled the transmission. Low and behold the transmission now locks itself in 4th gear. It wont do this all the time, in fact 90 percent of the time it shifts ok, but then it decides to lock in 4th and there is absolutely nothing you can do to free it without splitting the tranny. Apparently those fingers that have been omitted on the new part are really important because they keep this from happening. They keep the three synchro locks that operate inside the synchronizer hub from riding up on the synchronizer ring. Once a lock rides up on the ring the synchronizer sliding sleeve cannot move back to neutral. This could be potentially dangerous. Here are some pictures to illustrate what I am talking about.

This is very disappointing as the transmission was finished by the time the problem became apparent and now I have a lot of shop time invested in a part that does not work in this Porsche!
_________________
87 924s
88 924SE gone
447 hp cgt clone
87 924S gone
84 944 sold
83 944 sold
89 turbo S LSD, ABS etc
86 951 white rocket
85 944 sport everything.
84 944 sold.
87 944 sold

GeorgeV · Posted: Wed Dec 11, 2013 10:05 pm Post subject:

are saying Pelican gave you a dud part, or are all the new synchro rings made wrong?
_________________
1981 932 with mods:
http://www.924board.org/viewtopic.php?t=37921

larchie · Joined: 19 Jun 2003 Posts: 297

Part Number for the LASO Synchro Ring (2nd-4th Gear) at AutoHausAZ, AutoAtlanta, GermanAutoParts, and several others is 016 311 295 without the extension modification m59. Could a difference in rings be marked by that extension modification of m59?

LASO in Germany doesn't list a 01 311 295 m59 Synchro Ring:http://www.laso.de/home.php?width=&height=&lang=en&id=1003&such=016+311+295+ -- just the PN 016 311 295. There are other PN extensions besides m59 available at this part number from other suppliers also, but I don't know if this might be a difference which makes a difference.

joecitizennn · Joined: 12 Sep 2005 Posts: 2096 Location: no mans land

If you look on the pelican website for synchronizer rings you will see that gears 1 and 5 are genuine Porsche parts where 2-3 are Laso brand. Look closely at the pictures and you will see that rings 1 and 5 have the appropriate finger to check the synchro lock, but the off brand Laso 2, 3 and 4 synchro rings have been changed from the original design. Pelican does not offer the original rings for gears 2-4.

The following company is selling OE Porsche rings. All gears 1-5 have the correct design.

http://www.design911.co.uk/fu/pt376_915_-cma81-cmo83/Porsche/924-1977-88/Gearbox-Parts/

I contacted Pelican about this issue and they did not have an explanation. The Tech and I came to the conclusion that while Laso carries the original part number, they changed the original design.

I am returning my parts to pelican for a refund. I hope they refund shipping too. I am going to have a lot of hours in this transmission.
_________________
87 924s
88 924SE gone
447 hp cgt clone
87 924S gone
84 944 sold
83 944 sold
89 turbo S LSD, ABS etc
86 951 white rocket
85 944 sport everything.
84 944 sold.
87 944 sold

sbarc · Posted: Thu Dec 12, 2013 8:50 am Post subject:

No doubt about it....this situation is a complete nightmare full of frustration.
_________________
1981 931 (Canadian car)
1981 931 (US car)
1990 928GT (ROW car)
1991 Toyota MR2
1989 Toyota MR2 Super Charged
1985 Toyota Supra
1973 Triumph GT6
1971 Opel GT

larchie · Joined: 19 Jun 2003 Posts: 297

joecitizennn · Joined: 12 Sep 2005 Posts: 2096 Location: no mans land

GeorgeV · Posted: Sat Dec 14, 2013 4:56 pm Post subject:

Definitely a PITA!
_________________
1981 932 with mods:
http://www.924board.org/viewtopic.php?t=37921

Rasta Monsta · Joined: 12 Jul 2006 Posts: 11723 Location: PacNW

Checked the Vendordrome for this. . .pics online of OE (1st and 5th) and Euromax (5th) show the fingers Joe wrote of. Pics online of the Laso part (2nd, 3rd, 4th) show no fingers. No other vendor comes up for these parts.

Did they supercede the sleeve to a different design?
_________________
Toofah King Bad

WeiBe (1987 924S 2.5t) - 931 S3

joecitizennn · Joined: 12 Sep 2005 Posts: 2096 Location: no mans land

In conclusion, pelican did come up with the correct part after a few years.

kevingross · Joined: 15 Apr 2015 Posts: 34 Location: Stow, MA, USA

I don't have the Laso part in inventory and so cannot compare it other than with your photo. I've used them in the past with no issues, but some years ago changed to using only the VW/Audi/Porsche part.

That said, I don't believe the missing "finger" is the source of your problem. I suspect it's there to provide a little extra insurance against knocking the detent (any of the the three square chiclets in the operating assembly) out of its place. Really, the square recess in the synchro ring keeps the detent in place. It takes quite a bit of abuse to knock them out of the recess, and normal transmission use wouldn't get you anywhere near knocking them out and up against the fingers. I've had a small number of race customers who've managed it, they were quite abusive to their transmissions. (They have all graduated to becoming former customers, thankfully.)

Make sure you've oriented the 3rd/4th operating assembly properly, with the wider hub facing 4th gear as the workshop manual suggests. Check also that the two springs point the same rotational way, offset 120 degrees in terms of the detents they engage. Again, per workshop manual.

BTW, the material used in the Laso part is brass, the VW/Audi/Porsche part bronze, unless I am mistaken.
_________________
Kevin
Catellus Engineering, Inc.
http://www.catellusengineering.com/
catelluseng@gmail.com

joecitizennn · Joined: 12 Sep 2005 Posts: 2096 Location: no mans land

The lock problem was induced during test shifting after assembly. The unit never made it back in the car with the Laso synchro to to get any kind of abuse. The new ring from pelican is identical to the original ring that broke. The transmission now shifts perfectly and is currently on the road.
_________________
87 924s
88 924SE gone
447 hp cgt clone
87 924S gone
84 944 sold
83 944 sold
89 turbo S LSD, ABS etc
86 951 white rocket
85 944 sport everything.
84 944 sold.
87 944 sold

Noahs944 · Posted: Tue Nov 08, 2016 12:56 pm Post subject:

Any idea if the syncros are the same in the audi 924 4 & 5 speeds as with the 944 5 speeds (turbo/non turbo trannies)?