Engine/Transmission (1998.5 - 2002) NV4500 Transmission Failure

[MAYoung]

Today's Update 03 Feb 2009

For today, I was able to remove the transfer case and am now working on the rear cross member. The bolts are fairly snug but are coming. Work is progressing slowly as I am cleaning parts and surrounding structures as I go. (That is what 11 year of mountain driving brings to your truck. ) Next step, the actual transmission removal.

 

[MAYoung]

Update as for February 4, 2009



Gentlemen:



As of 11:30 PM PST, February 3, the NV4500 has been removed from the 2500. The rear cross member was not as horrible as I expected. I simply removed all eight bolts and carefully tapped the cross member upwards and then towards the rear of the truck. It took about 5 minutes of tapping and fussing to get the cross member out. The bolts were much more difficult and time consuming.



Not being able to see the back-up light connector on the top of the transmission was a pain. I was finally able to disconnect it once I lowered the transmission slightly.



I accomplished this alone with just jacks and hand wrenches. I purchased a 3-ton floor jack with a plate adaptor. I strapped the transmission to the plate with the straps that came with the plate. Everything went smoothly as I worked slowly and lowered the transmission first followed by the jack under the engine by small amounts. (I would strongly recommend straps with ratchet style tighteners to really hold the transmission to the plate. )



The transmission and transfer case are going to the transmission shop tomorrow. We will then evaluate the cause of the failure. I will keep you posted.



Thank you for all the input.



M. Young

 

[MAYoung]

Clutch Housing

Gentlemen:



I have removed the eight bolts on the clutch housing cover but it does not seem to want to budge. Am I missing bolts on the engine side of the housing? The Dodge Service Manual does seem to indicate that there are additional bolts on the engine side but I do not see these bolts.



I tried gently prying the housing in the gap on the bottom side of the housing but it had that feel of something still holding it in place. I am trying to be very careful so as to not to warp the housing.



Please advise.



M. Young

 

[SRadke]

The bell housing is held on by the 8 bolts you already removed. Also attached to it is the clutch slave cylinder that needs to be removed. After that you should be able to pry it off with the gap in the bottom. There are two alignment dowels approx 3/8" deep around two of the bolts that are currently holding it on. It will pull straight off those.

 

[MAYoung]

Update February 5, 2009



Gentlemen:



Thank you Mr. Radke for your prompt response on the bell housing. I was being very cautious on prying the housing as I did not want to warp or damage the unit. I will take a rubber mallet and thin pry bar to pop it loose.



Further updated failure analysis and questions: I got the NV4500 unit to the transmission shop (Trans Craft, Reno, NV) and as soon as the top cover came off, one could see the failure point. The drive gear on the input shaft literally melted off the shaft. That failure then destroyed the gear below it on the counter shaft. At a minimum, the counter shaft and input shaft + gear will have to be replaced. We will not know the extent of the damage to the main shaft until the unit is disassembled. Bummer. I was hoping for some type of simple broken gear or sheared shaft.



Why did this gear fail in this fashion? In simple terms, lack of lubrication. Where was the lubrication? The rear seal on the housing unit failed and the gear oil leaked from the unit into the transfer case (hence the reason for double the oil contained in the transfer case--12 pints vs 6. 5 pint capacity. ) I am told that GM NV4500 units would leak gear oil on to the ground but that the Dodge unit design would contain it within the two cases. Mike Dickinson of Trans Craft calls it a "silent killer" type of failure since unless you were changing the gear oil every six months, you may not catch the pending failure mode. What would cause the seal to fail? About 190,000 miles of typical usage.



Question time: Trans Craft is working up a number to rebuild the unit which he feels it can be done. I am most concerned about the reusing the parts on the mainshaft. Have they seen too much heat? Have the fine metal particles inflicted too much damage. One can visually inspect these units and the look ok but is the potential damage too great at a microscopic level??? How would ou ever know short of the ability to perform metalurgcal analysis?



I think that the economics of rebuilding the unit will determine the decision. If the costs are so close to a rebuilt unit from Standard Transmission or Blumenthal, I will probably go with a unit from those guys. Any other approaches to be suggested? (My historical preference is to rebuild one's damaged unit locally to control quality and have a local source to turn to with any problems. However, the appeal of a shop who rebuilds units on a near production line basis with lots of experience has its merits as well. ) But with a rebuilt unit from a third party, who knows what it failure mode was? You may ultimately get just as many stressed used parts as your own. Tough call.



My goal here is to return to a smooth and easy shifting unit that I have had in the past.



Thank you in advance for your helpful comments.

 

[kenny61]

I fried mine when it went low on fluid. The kicker is before I left on my trip I was crawling under the truck to check it when the wife came out with a honey do. I forgot to get back under the truck. 40 miles into my trip I remeberd 80 miles into the trip kaboom.
I now make sure I check it at least every 6 months and installed a temp sender in the new fast coolers.

One tip for when you put the transmission back in
get four bolts that match the 4 that hold the transmission to the bellhousing. Cut the heads off and use them as a guide to slide the transmission into the clutch assembly. Its a little hard to get it to go in straight when you are alone on your back under the truck

 

[BTighe]

congrats on getting her out.



just an fyi, radke wasnt bs'ing you about the hour timeline. he helped me upgrade the input shaft on my old truck. not sure how many but i know he's pulled quite a few of these.



i bought a truck with the 5th gear out already. i bought the nut from PDR and used an air chisle and loctite to put it back. not the best method but its got 20k on it and still going.

 

[SRadke]

You'll have several hundred dollars in each the countershaft (also called cluster gear), and the imput shaft. Add to that approx $25 each for syncos, $100 for a bearing and seal kit, whatever else they feel needs to be replaced, plus their time. I suspect your repair quote will be near $2000.

My advice is to trade it in on a rebuilt unit for Standard Transmission which will have the added benifit of coming from them with a new fully splined mainshaft and fifth gear locked down.

 

[MAYoung]

Update: February 5, 2009 #2; Flywheel Removal

Thank you for your inputs. I am slowly coming to the realization that a rebuilt unit maybe the best alternative. Mr. Radke is right in that it will probably top $2000 in parts in labor. If one had all the tooling and experience, you might tackle its on your own. However, if I were doing it myself, I would end up replacing a great deal more parts than probably necessary for a decent rebuild. On top of that, large shops say that they dyno test the units before shipment.





1) I was able to pry the bell housing off and removed the pressure plate and clutch disk. I have even removed the bolts to the flywheel. Now, how does one actually remove the flywheel from its snug fit? (Overall, the clutch was not in bad shape given 190K miles. )



2) Mr. Radke--Since you are from Oregon, have you ever worked with All Transmission from Portland? My shop in Reno uses they as their wholesale supplier and Trans Craft is recommending a rebuilt unit from them. (They are wholesale only. ) Their website does not detail the level of rebuild of the NV4500 so I prepared a list of questions to generate a comparison of Standard Transmission and Blumenthal's.



3) After the flywheel removal, I can see a little oil at the back of the housing. How much oil has to be present to require an rear crankshaft oil seal removal an replacement.



Thank you for your patience and support. I know progress seems slow. At least all the questions have come into focus and now I just need to complete the answers on the best path for getting the truck on the road.



Regards,



M. Young

 

[SRadke]

I have never used All Trans. Many of the local transmission shops use them but I've always delt with Standard Transmission and Gear.

With the flywheel bolts removed the flywheel will pull right off. Be cautions it does not fall on you, it is heavy. Typically while holding the top with one hand a thump at the bottom with the palm of the other hand will tip if off it's recess. The goal in this is to allow the flywheel to fall down to the aluminum lip 1/2" below so you can lift it off. I'll reiterate again, be carefull, IT'S HEAVY.

At 190k your rear main is probably due to be replaced. You'll likely see oil residue slung on the back of the flywheel, this is expected for the age. If you see liquid oil anywhere it definitly should be replaced. The seals are available from any Cummins dealer will come with an install kit and should cost approx $50.

 

[rubberneck]

I I'll reiterate again, be carefull, IT'S HEAVY.



At 190k your rear main is probably due to be replaced.

Good advice here. Those flywheels dont feel really nice when you get a body part in the way. Dont ask me how i know LOL. Since you have everything out it would be silly not to replace the rear main. Money well spent. The fully splined shaft is nice for 5th gear. At a minimum you would want to install an upgraded nut if you decide on getting a unit without the shaft. I lost 5th on my 98 last year with 140k on the clock.

 

[MAYoung]

Update: February 6, 2009 #1

Thanks to Mr. Radke, the flywheel has been removed. It just took a few firm taps with the hand and it fell down--it is HEAVY as Mr. Radke states. I estimate the weight to be 75#-80#. Not a good thing to drop on ones foot.



The rear crankshaft seal looks ok. No real signs of any leakage but I will go ahead and replace the seal since I hope not to be back hear again for another 190,000 miles.



I am going to replace the clutch with the OEM LuK part. The pricing from Standard Transmission was reasonable. If the orginal lasted this long, I will give the same product another run.



I am now leaning towards a rebuilt transmission. The question is weather or not to use All Transmission in Oregon or Standard Transmission in Fort Worth.



Thank you also to Kenny61 with his thread only "bolt" suggestion upon recoupling the unit to the tranmission. Excellent idea.



When I am done, I intend to write up my experience in a neater package since I am the quintecential shade tree mechanic. I am sure that someone could benefit.



Regards,



M. Young

 

[kenny61]

If you are even just thinking about future power upgrades go with an aftermarket clutch. I got the South Bend Clutch and Flywheel setup. I think I got a discount when I ordered both from Blumethals. If you know you will never mod it the factory will be fine. The first clutch I put in was a centerforce which was actually a luk . I dont think to many people here would recomend the centerforce but I put about 80 or 100k on it and it looked very good no cracks and little wear. I personally think the luks are fine for stock power. Ithink I had 70k or so when i pulled it out to upgrade my mainshaft. It lloked brandnew and I would have put it back in if it was a 2wd truck that only took an hour so to swap it out. When you have to do it by yourself on your back out side you really dont want to do it too often

 

[MAYoung]

Mr. Kenny 61:



Thank you for the suggestions. I keep the truck pretty much stock since it more than meets my needs. I will pull a heavy (10,000#) load about once a year for short distances. I normally pull a 2-horse trailer for my daughter that will max out at about 5,000# on trips of 300-400 miles. I do spend a significant amount of time in the Sierra Nevadas on largely paved roads but I am sure that the grades and snow (think rust) do add a penalty over flatland driving. The most significant change I have made to the truck is a fuel pressure guage. The rest of my time is spent maintaining the unit to factory specs so that it remains reliable transportation. One does not want to breakdown along side the road in California on a summer day with two kids, one trailer and 2 horses to boot.



This is the most serious breakdown for this vehicle. I have lost two VP44's but one was under warranty. (I have gotten smart about lift pumps. ) Now I am smart about NV4500's! (Sort-of). In any event, these trucks all require a learning curve to discover all their failure points and how to avoid them.



Again, thanks for the suggestions.

 

[kenny61]

One does not want to breakdown along side the road in California on a summer day with two kids, one trailer and 2 horses to boot.

Or rupture a fuel line On I-95 600 miles from home with a Mother, Wife 2 7 year olds, dog and 35' travel trailer



or, Smoke your NV 4500 on I-87 86 miles from home with a wife, 2 9 year olds and 3 quads stuffed in the bed





#@$%!:-lafOo. :{

 

[MAYoung]

Update: 06 February 2009

Gentlemen:



The rebuilt transmission and new clutch kit will be ordered on Monday.



I am going to Cummins to get the rear seal kit tomorrow and will see if it can be installed over the weekend.



Part of the weekend will be spent cleaning off grease and repairing rust points on the underside of the truck. I may have time to replace the vacuum pump and adapter gaskets/rings.



I am nervous about the shops returning the core charge. The shop I have been dealing with in Reno says the case is rebuildable but a $1450 transmission could turn into a $2000 transmission if the core charge does not come back. Has anyone had any problems with Standard Transmission or Blumenthals?



Regards,

 

[kenny61]

To be honest the 1 problem I had with Blumethals was getting the to pick up the core. After 3 calls and still no pick up I decided to keep it. They charge for picking up the core so iIsaved on that and I still have a ,I think , rebuildable core in the garage. I know most of the parts are still useable or of value. I think for the most part as long as the case is still useable they will give you back the money. I would call the companies and ask exactly what they consider an unusable core

 

[MAYoung]

The cores are valuable. You can get $600-700 for a core that is rebuildable. Apparently offroaders love the NV4500 for thier projects.

 

[rubberneck]

Yes they do. I have a buddy that put one in a jeep scrambler. YOu might try just putting an add in craigs list or the paper and sell it locally. Would save you the hassle of shipping it back.

 

[MMeier]

Gentlemen:



The rebuilt transmission and new clutch kit will be ordered on Monday.



I am going to Cummins to get the rear seal kit tomorrow and will see if it can be installed over the weekend.



Part of the weekend will be spent cleaning off grease and repairing rust points on the underside of the truck. I may have time to replace the vacuum pump and adapter gaskets/rings.



I am nervous about the shops returning the core charge. The shop I have been dealing with in Reno says the case is rebuildable but a $1450 transmission could turn into a $2000 transmission if the core charge does not come back. Has anyone had any problems with Standard Transmission or Blumenthals?



Regards,

No problems with core charges being returned on either trans I bought from Blumenthals. (4500 & 5600) I returned the getrag core when i did the 4500 conversion myself since I had to go right by there the folllowing week, just check with them about 2 weeks after they get it back, since it has to be torn down and inspected.