New 3-4 Syncros for NV4500

[Big MAK]

Having this done today and tomorrow. 78000 miles on it, heavily bombed for over half those miles and moderately bombed the rest (moderately bombed now). 4x4.



This happen to anyone else? I attribute it to pegging the RPMs on 3-4 shifts under heavy load to keep the RPMs in the power band. Although that first season towing the rockies w/o a e-brake probably didn't help either. transmission braking like a mad demon the keep the brakes from getting smoked and they were still pretty mushy at the bottom of the hills.



Expensive job, $540 for the gears alone, plus another $100 or so for seals, $750 labor.



If I had the money laying around I'd ask for a six speed.

 

[klenger]

I suspect that there would be a good future in 5 speed to 6 speed conversions if someone could get the price to a reasonable point. After owning my truck for a few months, my feeling is that the 6 speed is the only manual that should be offered becuase of the narrow power range of the ISB. Even driving empty, I find myself shifting too soon and falling below the desired power range. I don't think I'll ever miss the additional power of the ETH that much, but I'll always wish I had the DEE.

 

[Joseph Donnelly]

Mark, did you call 800-std-tran and ask them for prices? The ones you quoted seemed high. I have bought a number of gears and sychronizers from them and they also offer exchange units. Hope this helps.

 

[blackbeast]

Mark,



My 99 lost it's third gear syncros at 10k miles. DC put in a new 4500 for me . No questions asked. Gene also lost some syncros. I really hope we aren't seeing the start of a pattern here.

 

[TowPro]

Mark, what kind of oil were you running? Not that I think the oil caused a syncro to break, just wondering what kind it was, and how did it look inside?

 

[Barry Fuller]

I am curious about any symptoms other than major

grinding noises. I had some "hard" shift problems on the last pull over the Siskious when going from 4th to 3rd. Never did make noise - just did not want to shift. Have since changed oil(syntorqu)but have not done a hard pull while towing. In other words it seems to work fine while I'm empty but I do have some concerns for the future. Of course 5th gear is still to come! 55k and counting.

 

[Jff24Gordn]

Gene (MGM) lost his due to a warped 3rd gear, and it forced the 3rd gear syrcons to work really hard to get 3rd to match up.

 

[rrexcavate]

1999 5speed 3500

I have 66,000 on my 99 5speed dually. I work it hard pulling backhoe and skid loader up and down steep grades in Ozarks.

I have lost 3 & 4 gear syncs now 2x!!

 

[Sled Puller]

Check with www.enterpriseengine.com. ask for Doug.



They changed the material in the synchros at LEAST once, make sure they are not giving you NOS! Tell him you want the updated synchros!



It ain't the Castrol or the Amsoil, it is a poor design, and/or lowest bidder on material.



Mitchell's also do 6 speed conversions, you guys may want to price one.

Although from what I have seen on this board, the 6 speeds have their own problems. We can't win it seems.

Gene

 

[Big MAK]

Picked up the truck Friday night, drives real sweet. It appears the tech that did the work did a good job! Woodhouse in Blair, NE.



Had new rotors and pads put on it too. First time in 78000 miles my brakes don't pull! Could of been rotors all along?



While they had it apart he fixed the fifth gear nut and the tech had the good sense to put in a new input shaft and pilot bearing. Kudos to him. I'm pleasently surprised since it was at the dealers and doa so I was at their mercy. Used all dealer parts since the breakdown caught me by surprise; but the dealer has told me on other items they'd install whatever mfgs parts I brought with me (not under warranty of course).



The first symptom I had with the synchro failure was it wouldn't go into ANY gear. Shifted out of third downshifting to second at a stoplight and it came apart there I guess. NO gears. Let it set awhile and I could force it into fourth. Drove it awhile in fourth (clutch smoking... yep, 4th from a dead stop) and things shook out and I could shift but 3 to 4 and 4 to 3 would grind severely. Now that I think about it I always had a little 'catch' going 3-4 but my first NV4500 w/ Cummins did that too so I don't think it was symptomatic. Now it's amazingly smooth.



FWIW, I think the NV4500 is an awesome transmission despite this episode.



I looked into the NV5600 and it isn't a direct bolt up. The transmission is longer so mounts probably have to be re-drilled the the driveshaft would have to be shortened.