Help!! - Nash 4 + 3 - No Reverse
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Joined: Jan 2005
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Help!! - Nash 4 + 3 - No Reverse
Would like to get a quick input on why I have a manual Nash 4 + 3 - 4 Speed transmission and now my reverse gear is "slipping" real bad, almost to the point of not pulling at all. 
This is an '85 with original transmission.
I thought with a manual transmission, it either pulled or it didn't. I have always associated slipping, with an automatic transmission.
Please help...
85_TPI
This is an '85 with original transmission.
I thought with a manual transmission, it either pulled or it didn't. I have always associated slipping, with an automatic transmission.
Please help...
85_TPI
Racer
Joined: Feb 2005
Posts: 398
Likes: 1
From: Kelowna BC
It could be the clutch, but if that is alright, must be the direct on the OD. I am not sure how the OD works on the reverse, but I assume it is in direct mode.
I guess that is kind of stating the obvious, hopefully someone else will jump in with more info.
I guess that is kind of stating the obvious, hopefully someone else will jump in with more info.
Thread Starter
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Joined: Jan 2005
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Yea, first thing that comes to mind IS the clutch but it seems to do fine in the forward gears.
That OD has, as I understand it, been the source of issues with this tranmission, since it's inception. Someone else stated that Doug Nash lost the house from trying to warranty the box!?!
Does anyone know if there's a place in the archives where the Nash Overdrive is discussed?
thanks much,
85_TPI
That OD has, as I understand it, been the source of issues with this tranmission, since it's inception. Someone else stated that Doug Nash lost the house from trying to warranty the box!?!
Does anyone know if there's a place in the archives where the Nash Overdrive is discussed?
thanks much,
85_TPI
Melting Slicks
Joined: May 2002
Posts: 2,263
Likes: 414
From: Muskogee OK
Cruise-In VI Veteran
Check the ATF fluid in the OD unit, sometimes when it is low it will slip in reverse. happened to mine when I changed the radiator out and had to replace the amount that was in the raidiator. Hope it goes well for ya 
Last edited by flannel_man; Apr 2, 2005 at 05:44 PM. Reason: wanted to subscribe
Thread Starter
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I got the car up in the air and pulled the plug from the trans & OD units.
- The OD unit leaked black/grayish looking oil out, all over my Georgia Bulldogs Sweatshirt!!! 
- The trans unit was low on the gear dope. I couldn't even reach any with the tip of my small finger.
I removed the radiator a few months back and had it worked but I never even checked the ATF for the OD unit until now.
Could I have caused damage??
But it still surprised me to not find the gear dope in the manual box.
That's easily fixed but wouldn't think that would be a cause of my reverse gear slippage problem but I could be wrong here too.
I checked out the DougNash 4+3 OD section at the http://www.5speeds.com/dne.htm website and they did some pretty good talking on how/what/why you want to keep the 4+3 and just fix the problematic issues with it.
Makes meBrain think somewhat...
Thanks for any further assistance/input on this.
85_TPI
- The OD unit leaked black/grayish looking oil out, all over my Georgia Bulldogs Sweatshirt!!!
- The trans unit was low on the gear dope. I couldn't even reach any with the tip of my small finger.
I removed the radiator a few months back and had it worked but I never even checked the ATF for the OD unit until now.
Could I have caused damage??
But it still surprised me to not find the gear dope in the manual box.
That's easily fixed but wouldn't think that would be a cause of my reverse gear slippage problem but I could be wrong here too.
I checked out the DougNash 4+3 OD section at the http://www.5speeds.com/dne.htm website and they did some pretty good talking on how/what/why you want to keep the 4+3 and just fix the problematic issues with it.
Makes meBrain think somewhat...
Thanks for any further assistance/input on this.
85_TPI
Instructor
Joined: Jul 2000
Posts: 203
Likes: 3
From: Galesburg IL
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Racer
Joined: Aug 2004
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From: Stockton CA
Originally Posted by redwing76
So how come no-one replaces the DNE with a 5speed out of a IROC?
Near as I can tell to rebuild a DNE is about $2,500.
The DNE got better with age.
Near as I can tell to rebuild a DNE is about $2,500.
The DNE got better with age.
As soon as mine goes out I'm getting a 5 speed.
Race Director
Joined: May 2003
Posts: 10,749
Likes: 41
Originally Posted by 85_TPI
Would like to get a quick input on why I have a manual Nash 4 + 3 - 4 Speed transmission and now my reverse gear is "slipping" real bad, almost to the point of not pulling at all.
This is an '85 with original transmission.
I thought with a manual transmission, it either pulled or it didn't. I have always associated slipping, with an automatic transmission.
Please help...
85_TPI
This is an '85 with original transmission.
I thought with a manual transmission, it either pulled or it didn't. I have always associated slipping, with an automatic transmission.
Please help...
85_TPI
i had that same problem and it was my clutch, i changed to a centerforce clutch. I also had problems in forward gears.
Instructor
Joined: Jul 2004
Posts: 186
Likes: 1
From: ny
the 5 speed from the camaro to the best of my knowlege was never put behind a 350 (and therefore iroc as well i believe because all irocs were 350's right?). the 5-speed couldnt support the torque of the 350 and i guess wasn't much stronger than even the 305 put out.... so they often had problems...
tj
tj
Drifting
Joined: Mar 2003
Posts: 1,828
Likes: 212
From: Charlestown IN
Cruise-In V Veteran
Go find Scorp in the C4 Tech/Performance section. He knows these puppies inside and out. If you do a search in that section on 4+3 stuff, you'll get a bunch. The reverse slipping is a sign of the OD going out, however, throw some fluid in it, and see what happens. I bought a suction gun from NAPA to put fluid in mine. Slickest way I've found. In the event of replacement, other years will fit. I have an '88 OD in mine. Works like a charm. Doesn't use the cable on the TB. I do believe a 6 speed will jump right in there, if you're lookin' for a change. The best to ya 
Pro
Joined: Jun 2004
Posts: 646
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From: Santee Ca
Originally Posted by tjm2070
the 5 speed from the camaro to the best of my knowlege was never put behind a 350 (and therefore iroc as well i believe because all irocs were 350's right?). the 5-speed couldnt support the torque of the 350 and i guess wasn't much stronger than even the 305 put out.... so they often had problems...
tj
tj
2nd Gear
Joined: Nov 2021
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Melting Slicks
Joined: Jan 2014
Posts: 2,187
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From: Lunenburg MA
The OD fluid should be red ATF. Since you're also low on gear oil, I suspect the seal between the trans and OD may be leaking gear oil into the OD. '85 was not a good year for the 4+3, especially if not well maintained.
Melting Slicks
Joined: Feb 2003
Posts: 2,677
Likes: 811
From: Saskatoon Sask.
I'm going to go out on a limb here and guess that after 16 1/2 years, the OP has had some kind of closure with his problem.
Melting Slicks
Joined: Feb 2003
Posts: 2,677
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From: Saskatoon Sask.
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