NSBU.... again!!

[mark45678]

Does any one know what the deal with the "black and tan" ones Mine has the black one and the dealer has one on order ?but a parts guy had a black one in stock but says there is a new part number and will take a few days to get the "kit"? can some one tell me what the "KIT" is and whats in it? :(

[mdrag]

mark 45678910,

The tan NSBU switch is the new and improved swiitch, while the black one is the old style. The 'kit' includes the new tan switch and a black plastic cover that goes over the selector shaft.

Check the KD EXHAUST or BIG WHEELS link in my sig for pics of the old vs new NSBU switches. The box in the pics is from the new switch and has the Allison part# for the kit clearly displayed.

I ordered my NSBU switch kit directly from an Allison dealer for about $53.

[ 12-04-2002: Message edited by: mdrag ]</p>

[chiefsshop]

the tan nsbu is the updated switch, which is the one you want. I bought mine from the Allison dealer about three weeks ago for around $50. the box just contained the switch and as far I can tell was not a "kit". Took a few minutes to install and I was back to hauling ***. Please note, if the connectors are stuck in the switch, heat them up with a heat gun to loosen them, mine had a glue like substance that made removing the connectors a little difficult.

[gardnerteam]

Most Allison dealers are stocking at least 2 of the new switches according to Pacific Detroit Diesel Allison. They also told me they are automatically replacing the old ones on every transmission they have out, with Allison acknowledging there is a problem with the old one and recalling it. Of course, it doesn't cover GMC or Chev, but my Allison dealer says everybody including GM was told about it. My GMC dealer says "duh, GM has said nothing" I bought a replacement from Allison, have carried it as a spare, but now am going to have it replaced on my $ (1 hour quote from GMC). Better than a breakdown. Gotta love GM for the pride they take in taking care of their customer.

[mark45678]

I got a price from a chevy dealer {that I dont know} of 145.00 for the kit???? old black switch 45.00???? Any how thanks for the quick reply and any and all info is welcome!!!!
Mark ;)

[deadlyman]

what is this switch if you don't mind me asking

[Hound]

Mark, $145 for the kit is OUTRAGEOUS! Take a look at www.allisontransmission and find yourself a distributor who is in your area. It shouldnt cost any more than about $55.00 for the kit with the new cover.

[1822]

This NSBU topic is confusing. My GMC dealer on LI is a large truck only dealer and the service manager told me he has had no troubles with this switch. Another ind. diesel shop I use, deals with Allison directly and told me he has not had problems either. The Allison rep. told him that the bad switches are on non-GM vehicles which were spec. out differantly and that the GM ones are OK. Does any of this make sense to anyone. My next trip will be to Atlantic Detroit Diesel/Allison which is close by and ask them. They do all the NYC transit busses and FDNY fire trucks so they should know.

[mdrag]

1822,

Try a search using NSBU and read through the posts. IIRC, there have been at least 4 forum members where this switch has failed RECENTLY. The failure rate MAY be low, but for less than $55 to R&R (if you do it yourself), I feel it is cheap preventative maintenance to avoid a breakdown while on the road.

I find it hard to believe that the switches GM installed are not affected. My guess is that the commercial trucks are seeing more failures due to increased use - and with time, our trucks will start to do the same...

mdrag

[77TransAm]

chiefsshop, you might want to double-check... 29540479 should be a kit which includes the new tan NSBU as well as the small plastic shield that goes over the selector shaft.

deadlyman, a search for NSBU will probably give you more information than you could ever want, but basically it is the switch that tells the Transmission Control Module what gear the driver has selected. The old style NSBUs have a tendency to fail in salty or slushy conditions, and when the TCM doesn't know what gear you've selected it decides to give you no gear, or at best only third gear, which is the hydraulic default.

1822, the GM dealer won't have anything to do with the campaigns for the NSBU switch - Allison distributors administer all warranty claims for medium duty trucks, so the GM dealer won't see them return for that problem. The same switch was used on all trucks, pickup and medium duty, and it fails at about the same rate on all of them.

[Turbo Al]

1822 my second switch is now acting up, the first one was replaced at @ 5,000 miles (cover was cracked) and the replacement one is now acting up @ 22,000 miles (17,000 on switch) both were the old style.

[sonofagun]

mdrag,

What is the Allison part no. for the new kit?

Thanks,
Bob

[Jomar]

Will someone that knows, please post the Allison P/N for the NSBU. Thanks,


Jomar

[Hound]

It's the same number that 77TA posted. 29540479.

[62dog]

On my way to work this morning I noticed the PND321 display on the IP was not on. After driving for about 10min down a gravel road it came back on. This is the first time it happened, there was not shifting problems. Does this sound like a NSBU problem, it is salty and slushy here.

[mdrag]

son of a gun and Jomar,

If you check the BIG WHEELS or KD EXHAUST link in my sig and look at the pics in the Allison NSBU album - the Allison part number for the 'kit' is clearly displayed on the box.

Read the second post in this thread for my sig... ;)

[mackin]

62dog

It is one of the signs of early failure.....If your aware that you have the OLD style switch, and I know it stinks you have to come out of pocket, but I'd stick one in my glovebox with the install someone posted on another thread.....

I still haven't heeded my own advice even although I found out my dealer (Allison) is letting them go for $45 bucks and change, and has a bunch..... :eek: Not bad, I could start a distribution center......

MAC

[zsqure]

Last week in the middle of pushing snow my gear selector indicator went blank and then came back on. Clunk reverse, clunk drive, ses light oh sh#* not now. No power at take off, clunking tranny should I drive it until it blows? (After all its under warranty.) Plow for another hour decide to call the dealer, they can look at it (it's 4:30) bring it right over. They tell me the error code indicates reverse solenoid they kept it overnight and had it fixed by 10:00 the next morning. The dealer replaced switch PN12050016 have no idea what that was. Works fine now. No power was due to being in limp mode I think it was stuck in 2nd gear (40mph 3000rpm)
Here is what they wrote " 30185 scan pcm codes p0847 p0857 p0872" While in they replaced the leaking cab light with a new gasket and changed the oil.

[77TransAm]

zsqure, the part number for the old black (failure-prone) NSBU is 12450016. I wonder if they misprinted one digit and that's actually what they replaced. Unfortunately, if they replaced it with the same part number you are just as likely to have the new one fail. They really should have used the updated part number 29540479.

[SteveO]

Hi everyone..

The part number for the Tan NSBU w/shield is 29540479 just as 77transAm said..

I have replaced Hundreds of NSBUs in the past year.. Allison Transmission has a Campaign on the Black NSBUs which ONLY includes Freightliner and International Truck /bus.. The reason, those two are the only OEMs that buy that switch directly from Allison all others buy it from the manufacture

In the past 3 years I have only replaced about a dozen that were bad... In most cases UPS and Fedex (HUGE duty cycle on the switches) are the only customers that are having problems with the black..
Most of the UPS failures are in places like Chicago were the salt and sludge melt during the day then freezes later in the evening and it packs up against the nsbu... If you live in a place like that the Tan NSBU is better, but it's still going to fail..

Please note&gt; I have found the connectors loose nothing wrong with the NSBU.. Please check that first before replacing...

[hoot]

SteveO,

Welcome back. We missed you!