Doug Nash 4+1 Help

[Bobby Fazio]

I have a Nash trans with Liberty face-tooth gears. Heavy, but bulletproof. However, every once in a while, the thing will not go into 3rd gear going down track. It goes in third around the pits and on the return road but under 8000rpm load it won't. It does it randomly and it did it in 2nd round last night. It is not a clutchless trans and I have to use the clutch to shift so I put more pedal travel (We are at about .080 air gap) and I even tried granny shifting it in 3rd round last night and it still wouldn't go in. We've taken the trans apart a few times now and found nothing.. Everything still looks brand new. No problems going in 2nd or 4th ever.

Could the clutch be getting too hot in the burnout that it is not fully releasing? But why is 2nd and 4th never a problem?

[L79racer]

Go to this web site. Its for stick cars. A lot of the guys over there are running that trans. Look under tranny tech.
http://www.umtrnorth.com/Forums/default.asp

[Notch1320]

Have you checked the adjustment on the shifter stops?

[Bobby Fazio]

Shawn I haven't checked the stops because it seems to go in 3rd fine everywhere but on the track. I'll double check it though.

It's weird though because after I miss third, I quickly get off the throttle not to over-rev but even with the clutch still pressed all the way in and me coasting I still can't jab it in 3rd for those few seconds. I have to put it in 4th or neutral.

[gmonde]

check the detent in the trans its a steel ball with a spring,you mite have a bind from 2-3 and also the case holes for the shift forks ,as those transmission get older the holes start to elongate and that affects the detents ,,i used to run one and the holes where an issue,should have re bushed the case but sold the trans ,,pull the trans out and mount the shifter on the trans a try to duplicate the the shift but you will need an assitant to turn the input shaft ,you mite find something there gmonde

[FED 387]

If it is ONLY 3rd gear then Somewhere along the way you either missed a shift or ground a gear trying to get into reverse or it is time to service the trans and burred up either the slider or the gear or both on the mainshaft---a few things to look at also

#1--Double check your shifter arm bushings if you use them make sure they are not cracked or broken in any way you would better off with heim joints on the shifter rods anyway Hurst bushings or Mr Gasket used to work the best---change them FREQUENTLY

#2----Take the trans apart and look at the sliders or the main shaft gears if there are ANY burrs on the teeth it will not shift at hi RPM--

#3 if there are any burrs take a Dremel or carbide burr and dress them make sure there are NOT ANY burrs on the slider or the gear

#4---Have you removed the dogs in the gears if there are any in your trans?

#5 --check the shifter alignment pin and adjust the shifter so that that pin slides in and out FREELY with ABSOLUTELY no movement of the shifter arms while doing this

#6--- look at both of the holes in the shifter arms make sure they are not wallowed out and make sure you are using a locknut to attach the arm to the shifter fork stud

#7 air gap is not that important unless you are using a real aggressive clutch disc that gets more aggressive the hotter it gets then the disc will not fully release cuz it got hot and closed up the air gap

these are a few suggestion and not necessarily in this order but from my experience things that need to be checked

My guess is that the slider or the teeth on the gear need to be dressed!!!!Thats the first thing I would look at--if not that then look at the other things next --- good luck let me know what you find out-- I probably made 300-400 passes with a DNE2 trans and from trial and error learned how to make these things live and work well---Comp 387

[randy wilson]

Look at your hub, also. You might have a problem there. If so, turn you're slider one tooth and, the hub one tooth, and make sure it slides freely.

[FED 387]

Yes I forgot to mention the hub!!! The ends of the teeth should almost be just slightly rounded like this ) not like this ] if you understand what I am saying---also make sure that both the slider and the hub have no burrs on them try to slide them together and if you do feel ANY burrs they will probably be a cause for your problem--comp

[Mike Taylor 3601]

I'd say slider/dog problem,but a few more things has bellhousing been checked for alignment? My brother had one out he told me drive it maybe I can't drive,I can't remember if it was 3 or 4 or both but it was like you hit a wall with shifter would not go wide open or even the shameful Granny shift. BTW the term Granny Shift offended my Granny's,God rest their souls. His bell was like .050'' out and was way out of parallel we had to find guy with blanchard grinder big enough to true it up and we centered it.After that would fall in gear,still will need to service sliders/dogs once they are wore they will actually push apart instead of engaging.
Also make sure pilot bearing is good input out of line from bell or loose pilot bearing will let input move and keep from shifting.usaully misalignment high gear will be the worst but if you can't get high it's hard to tell.
You need to service trans and check all the things that have been mentioned in all these posts so you got it right and will not problems shortly.
If you have problem with pilot bearing the only type I have seen that will last is bearing w/sleeve on od that fits in the big hole where,please excuse my language,but i'm just gonna say it ''torque converter'' centers,well anyway on chevrolet.Jerico sells them
I had slider getting bad in Nash one time if you did'nt hold in would jump out of third when jumped out kept pushing when it bumped high side would go back in and most people never knew anything happened.
Mike Taylor 3601

[FED 387]

Forget to also mention input shaft and checking the runout on the bellhousing but I would of thought he had already done that---pilot bearing to use is from GM 6.2 diesel its a roller bearing same one Moroso sells also offset dowel pins from Moroso for bellhousing lets you move it where ya want it---you'll need a dial indicator with a magnetic mount on the crankshaft to check run out--get used to taking this trans out/apart only way you will solve your problems----after ya take it out and BEFORE ya split the case make sure you install the nuts on the shifter forks otherwise they come out and you'll need a long skinny screwdriver to get the detent springs and balls back in---ya gotta service these things every 40-50 runs check the sliders -hubs-dogs- grind the teeth--- check reverse idler gear also if my memory is correct 3rd gear runs the reverse gear so if ya ground it trying to get into reverse ya mighta screwed up 3rd too--Comp 387