I was just wondering how heavy any of you tow in 5th gear with the NV4500. Are you worried about the nut backing out or do you just pull anyway? Also is weight a factor as much as wind resistance is?

 

Lugging it with a heavy load or for that matter lugging it period is the worst you can do for your fifth gear. I tow a 8500 fifth wheel in fifth gear when possible and I can keep the rmp's up over 1500 or higher. I will not have mine secured till I need a clutch or it works loose itself. Goodluck,,,Rick One more thing my 97 has 72k miles and 95% of those were pulling the RV as I do not use it for a daily driver, some lose the fifth gear some don't,I have been told it is just a matter of time and not if it loosens off??

 

Just don't suck it down past 1600 in fifth gear when pulling, at lower rpm like that, it develops a vibration that assists in loosening the fifth gear nut, and viola, no more fifth. I have seen one case in particular where the nut backed off, and somehow the tranny also wedged itself in fifth. Had to pull the whole thing to repair, not just the rear case.

I do a lot of towing with my 01, NV4500, and so far I have had some decent luck with the tranny. It seems to be all in how you treat it.

Good luck

 

I never worry about mine, i guess when or if it breaks ill fix it.
75% of my driving im towing something. Trans has treated me well.

 

I towed in fifth for six years with my 97 2500 with no problem. I NEVER let it drop below 1600 RPM and that may be what prevented the nut problem. Casey

 

personally i never let mine go under 1900, plus you dont pull with more then an extra 45hp, on my 5th tranny so i've been their. I also run an extra qt of oil in it .

 

I dont understand what you just said. You dont pull with more than an extra 45 HP? And have you replaced the whole tranny 5 times?


Great responces, too, but I was also wondering how HEAVY do you guys pull in 5th or would that even matter? I could see where a 8-10k TT or 5th wheel would be harder on the gear than a 4-5k flat bed. Or is it all the same?

 

i pull a 5th wheel trailer at 10,000, and a goose neck with up to 15,000 using 5th gear and have not had any trouble yet.135,000 miles,i do not lug it in 5th, 1750 rpm or so then down shift.

 

I think the key is not going below 1800 or so pulling. I ran mine for 186k, never had a problem with it. Then changed to a nv5600.

 

i was told the main problem is that with my tst box being 2nd stage 90hp that it is putting out to much torque for what i'm haulin weight wise . as far as tranny yes rebuilt twice two news and then the original. first three the gears had the teeth stripped off of them the first new had synchro problems. the lighter the trailer or load the less the problem.

 

Thanks for the info. Thats what I was looking for. My problem is that with 285's (which I know lots of people running that big of tires or bigger) 60 mph is around 1600 RPM, so for that reason I run in 4th. Living in CA I dont feel safe, financialy, pulling over that speed unless I can clearly see far back for the county mounty.

 

I personally don't tow below 1,800 RPM.

Which is perfect for me and my stock size tires and 3.55, I'm almost always towing in 5th at 1800-2200 works awesome.

 

I gross out at 19,300 lbs GCW and tow in 5th without even thinking about it but don't go below about 1600 rpm at that weight in 5th - it just won't pull that weight that low in the rpm in 5th without some serious lugging.....the revised 5th gear nut in the 98 model year greatly reduced these failures.....I have a friend who runs a 97 3500 CTD tow truck which is heavily bombed and has had 2 5th gear nut failures in 800,000 km and the 3rd fix had the revised nut fix which has now lasted over 250,000 km with no problems......this is on a truck that is 10,300 lbs empty and frequently grosses 18,000-20,000 lbs GCW.

 

Thanks for the uplifting info, but I was wondering if you know what the revised 5th gear nut is? I have even read of guys actually trying to weld the nut on and having the weld break.

 

here is a link with some good info along with different attemps at fixing the nut. down the page alittle is a picture of the different nuts that have been used, and then there fix for the nut problem.

http://www.quad4x4.com/NV4500%205th%...s.htm#Nut_Woes