just got my new truck and love it just have a question about my nv4500 recently ive noticed when downshifting from 5-4 it comes out of 5 easily but doesnt want to go into 4th. if i come out of 5th to nuetrual and release the clutch then clutch it again it goes in fine.
Also sometimes when going from 4-5 it skips that fist "little shift" before it actually goes into gear (syncros maybe????)feels real loose and grinds a little bit b4 it goes into 5th. anyone know whats up?

 

I'd guess your synchros are getting worn. I would've thought that 3rd would be worn out before 5th, but different trucks, different usage.

 

anyone else agree or have a diff opinion?

 

try overfilling the trans by 1 quart, might help but syncros. sound worn.
you can add a qt. of lucas oil stabilizer should help with shifting its really takes 75wt. syn. oil. you can take the shifter boot loose and pull the shifter and pour it in like that its not hard at least on 2wd don know about 4wd.

 

it seems to not do it when its cold while im on my way to work... maybe because the oil is cold and sticks better? maybe the lucas stabilizer is a good idea, is it a synthetic blend or is their a special kind for synthetic?

 

I seem to remember a problem in the 4500 with the 5th gear shaft nut backing off but I can't remember how to check if your tranny has been serviced of this. Maybe someone else will chime in. I would say change the oil if you haven't already but the old "gummy" oil might be keeping the nut on if this is indeed a sign of that issue.

 

i know the guy who owned it before me did tow but i dont believe it is the nut, it has no problem going into 5th, its doesnt like going into 4th from 5th. but it all shifts smooth when the oil is cold im assuming so nice freash oil and a lil overfill might helps things. does anyone know if the lucas oil stabilizer is safe for the NV4500?

 

I would NOT add Lucas to my 4500. It calls specifically for Castrol Syntorq....NOT syntek(Spelling). Or the Chevy/Chrysler equivalent. You can also use the Amsoil equivalent. That is what I run. The syncos are very sensitive to the the wrong fluid. when shifting gets a little tough, I'll drain and refill. Just my experience

 

Dump just a little bit of oil out and see what colour it is. When I changed my fluid out after I did my clutch, it was still a nice honey colour. I ran Redline in it afterwards, my 2nd, 3rd, 4th and 5th gear synchros were all hurting. Oil came out very dark. My replacement tranny (had 410k km on it when it wen in and was 13 years old) still had nice honey coloured oil in it, and I replaced it with the proper fluid this time. Its holding up much better than the last one right now. Point of the rambling, the old oil might still be good, and you can just top it up.

 

okay thanks for the info i went to the chevy dealer and got the semi-synthetic synchromesh fluild for 12$ a Qt. and ill skip the lucas stabilizer

 

Make sure it is for the NV4500, as it has its own special fluid. When I bought mine, it was $25/litre at DC, $30 at GM. $12 seems low, but everything is overpriced where I live.

 

it was originally 16$ a Qt. but the guy said he could cut me a deal... im not sure if the 4 dollars makes a difference. and it wasnt actually a chevy dealer it more more of a large truck dealer that sells mostly GMC trucks. prices seem more reasonable

 

You don't want syncromesh, that's the lighter duty stuff. You have to get Syntorq, ask for it by name and make sure that's what you get, it is different.

 

GM used to use nv4500 trannys so a GM dealer might have Syntorque in stock for less $ just because they don't sell much anymore. As far as 5th to 4th shifting, mine has always been kinda tight I 4th, so it may be nothing to worry about. When I downshift to 4th, I do pause for a second in between gears. Good luch

 

i got sick of trying to find the right fluid so i returned the GM stuff and ordered Amsoil MTG. i think i might need some new 5th syncronizers anyone know where i can get them while its still under a warrenty... im gonna have my mechanic take it apart and look around while i put the SB-OFE in just to make sure, i also noticed theres some oil leaking out of the bellhousing, dont know if its motor or tranny -looks like motor but is isnt all that black- but there isnt much. i got the rear main oil seal and input shaft seal in the truck that im going to put in regardless while the tranny is out of the truck. if the oil leak is the tranny would that be causing the problem? im gonna check it after dinner so ill keep it updated.