Well darn... 4+3=No Reverse...
Thread Starter
Intermediate
Joined: Jun 2024
Posts: 25
Likes: 7
Well darn... 4+3=No Reverse...
I finally got my 86 running really nice after buying it non-running and doing lots of learning to get it going. Now it is quite the fun little car to drive, although it could use a paint refresh for wow factor.
Unfortunately, the reverse slips. It does move you backwards, but it makes a slipping sound and you can tell movement doesn't match RPMs.
The seller claimed the car has a new clutch, so assuming he was truthful about that, it sounds like the OD unit is on its way out.
I did check the fluid today as I was under there anyway to do an oil change. It was full, though likely due for a change.
Since the OD works perfectly in forward gears (at least as far as I can tell with my small amount of miles) would it be worthwhile to try a filter change and new fluid in the Nash? I am guessing not since it sounds like friction disks wear causing this condition. Just wondering if I have any options besides a swap or rebuild. For now, I plan to enjoy the car using straight through parking spots. LOL.
Unfortunately, the reverse slips. It does move you backwards, but it makes a slipping sound and you can tell movement doesn't match RPMs.
The seller claimed the car has a new clutch, so assuming he was truthful about that, it sounds like the OD unit is on its way out.
I did check the fluid today as I was under there anyway to do an oil change. It was full, though likely due for a change.
Since the OD works perfectly in forward gears (at least as far as I can tell with my small amount of miles) would it be worthwhile to try a filter change and new fluid in the Nash? I am guessing not since it sounds like friction disks wear causing this condition. Just wondering if I have any options besides a swap or rebuild. For now, I plan to enjoy the car using straight through parking spots. LOL.
Thread Starter
Intermediate
Joined: Jun 2024
Posts: 25
Likes: 7
I should also add I have changed friction disks before on a ZF6 auto trans in a 2011 BMW. That was not terrible, but from what I can tell the Nash requires some special tools? I would not want to go through the effort and waste my time.
I love ZF6s in BMWs, maybe that is the route... but I don't want to have to modify the car due to cost since I probably could not do those mods myself.
I love ZF6s in BMWs, maybe that is the route... but I don't want to have to modify the car due to cost since I probably could not do those mods myself.
Melting Slicks
Joined: May 2002
Posts: 2,263
Likes: 414
From: Muskogee OK
Cruise-In VI Veteran
So, when my +3 ( OD ) went out I lost reverse like that. I'm told that's actually how you know it's dead, you'll lose reverse to the point of nothing vs having all the 4 forward gears just fine, but I had no OD when I flipped the switch
Granted that was 20 years ago from the transmission shop, so who knows how accurate that statement was
Granted that was 20 years ago from the transmission shop, so who knows how accurate that statement was
Drifting
Joined: Sep 2022
Posts: 1,486
Likes: 395
From: Liberty, SC
2023 C4 of the Year Finalist - Unmodified
You'll also loose engine braking. the DPO had filled the OD gear oil. That polluted the clutch plates and caused the 'no-reverse-no-engine braking' situation.
On top of that, the main bearing had given up the ghost, moved forward (similar to what is described in the video) and scarred the OD cover. I bought another unit from a fella in CA that parts out cars and swapped out its bearing and cover. So, far so good.
Minus the bearing and the cover, I have most of the other various parts for the OD. If you end up needing something, let me know.
On top of that, the main bearing had given up the ghost, moved forward (similar to what is described in the video) and scarred the OD cover. I bought another unit from a fella in CA that parts out cars and swapped out its bearing and cover. So, far so good.
Minus the bearing and the cover, I have most of the other various parts for the OD. If you end up needing something, let me know.
Melting Slicks
Joined: May 2014
Posts: 2,895
Likes: 592
From: New Port Richey FL
He may not have filled with gear oil, when the OD isn't maintained or as in your case the sprag and general internals have seen the end of life the ATF gets a royal stink like gear oil. Good luck with the over haul hopefully you can get all the things you need
Burning Brakes
Joined: Jun 2005
Posts: 1,191
Likes: 15
From: Wallingford Vermont
I'm a little late to the party, but yes your OD is dying. STOP driving it. The front carrier plate will get damaged, a part NLA and very difficult to rebuild the 4+3 when it becomes scared up. Good luck trying to find someone to rebuild it. I gave up on my 4+3 years ago and converted to T56.
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Thread Starter
Intermediate
Joined: Jun 2024
Posts: 25
Likes: 7
I'm a little late to the party, but yes your OD is dying. STOP driving it. The front carrier plate will get damaged, a part NLA and very difficult to rebuild the 4+3 when it becomes scared up. Good luck trying to find someone to rebuild it. I gave up on my 4+3 years ago and converted to T56.
If I tear down this unit and don't find anything worn besides friction disks, are those something that I can source? I noticed 5speeds.com is out with no ETA but Cobra transmissions has some stuff. I guess it is a matter of just tearing it down first, seeing what is worn and what might be too far gone and order stuff at that point?