Had the 5th gear retainer nut installed by my local shop about 6 months ago and now 5th is hung in gear.  Just returned from that shop and was told they can't see any problem from shifter section on top of the tranny so it must be internal.   He told me he shouldn't have to pull the tranny since 5th is in the tail section, that just means a little less in labor.  This 5th gear is starting to $500 here $500 there me to death.  He hasn't pulled the tail section off to see what exactly the problem is but I am sure it want be anything to do with the retainer nut because that is what he put in and said I would never have the issue again.  So far he is correct I haven't loss 5th but now that is all I have is 5th.   Transmissions are one of the things I don't know much about but this is causing me to educate myself.  This 5th gear has been a problem for years in this tranny, so this mechanic should have a good idea on the fix.  I want to go back in Monday and let him know what I want fixed since he has had the truck 2 weeks and is still in the diagnosing phase.  What do I do now???????????

I've got to ask what size tires are you running? Then do you tow heavy trailers?

 

My OEM NV4500 went 265k miles before breaking the main shaft in half at the 3rd/4th syncro. Now I've rebuilt the transmission and now have 70k miles on the new transmission and no signs of 5th gear nut issues. I never had a 5th gear nut issue even on the first transmission.

3 minutes ago, Mopar1973Man said:

no signs of 5th gear nut issues. I never had a 5th gear nut issue even on the first transmission.

You must have lucky nuts. 

Not coming out of gear could still be because of that nut, be nice to know for a fact that he installed the retainer. It can also be something with a clutch or pilot bearing. Also something could be wore out on a fork or missing little plastic pads if this tranny uses them. 

The truck runs stock size tires, it's a flat bed cab and chassis.  Only ad-ons are 75Hp injectors and a FASS 150gph lift pump, but no means is it a hot rod.  The truck is mostly an empty everyday ,farm truck,driver but time to time may pull up to 20,000lb gooseneck.   I'm trying to make a decision on buying a new tranny because I'm still waiting on a diagnosis on truck.  If I buy a new tranny who do you recommend buying a reman. from?  I'm definitely going to learn how to rebuild trannies after these issues but until then I have to get truck back on the road.

Well it's not the 5th gear nut.  He is throwing some 1200$ rebuild numbers for the tranny but not sure I want him rebuilding anything.  So I need recommendations on where to get another tranny.  Oh and also before the mechanic knew how much a valair clutch cost he told me he kind of smoked the 6 month old clutch getting into shop.  Remember stuck in 5th.   This is going to get ugly before it gets better.   

I took mine to a local rebuilder for $1,800 to rebuild my NV4500. Mine I snapped the main shaft at 3rd/4th shift ring. For the $1,800 I got the upgrade main shaft. All brand new bearings. All brand new syncro's (carbon fiber). Then I tossed in a bucket of Mobil 50 SAE GL-4 Transmission fluid. So far I'm over 70k miles on this transmission and still running strong. Fluid is still clean and shifting smooth. 

 

http://www.wellertruck.com/loc.aspx (Boise Shop)

Edited April 19, 20187 yr by Mopar1973Man

I see there is a Weller truck in Houston which is about 45min from me.  My local shops don't rebuild manual transmissions they send them off to get done.  I'll Weller a call to see what they offer, I would think they are just as reputable down south as they are in Boise.

What is he trying to say that's wrong with tranny, and how stupid is he trying to drive it in 5th gear, he couldn't push it in a shop or come up with something. I'd be mad about clutch and expecting him to buy a new one, and no way I'd want his dumb as. touching transmission. Maybe I don't know the details but from what I hear he is an idiot. That sucks you have to deal with this. Did you look at it yourself to see if he in fact did install this or something similar.   https://www.ebay.com/i/131919575347?chn=ps&ul_ref=https%3A%2F%2Frover.ebay.com%2Frover%2F1%2F711-117182-37290-0%2F2%3Fmpre%3Dhttps%253A%252F%252Fwww.ebay.com%252Fi%252F131919575347%253Fchn%253Dps%26itemid%3D131919575347%26targetid%3D313776935016%26device%3Dm%26adtype%3Dpla%26googleloc%3D9018682%26poi%3D%26campaignid%3D833559251%26adgroupid%3D39417365901%26rlsatarget%3Dpla-313776935016%26abcId%3D1123856%26merchantid%3D6296724%26gclid%3DCjwKCAjw2dvWBRBvEiwADllhn0VKBuwdQ2RaVnYjVXk7iuA60bi-OqCVtQVtuTFVcBIipavfaS5h7BoCFjkQAvD_BwE%26srcrot%3D711-117182-37290-0%26rvr_id%3D1503681092566%26rvr_ts%3Ddbb60eae1620a860e1500cd1fffac3e7