nsbu switch?

[heartbeatcanada]

I was just wondering if anybody else has had there new and improved(ya right) nsbu switch fail on them. I had my original switch replaced last spring(no problems last year plowing) failed in springtime. Last week my new and improved switch failed after only 3 plowing events this year. Not to impressed at all. Has anybody else had there new switch fail? Was thinking of making up a metal shield somehow(haven't given it much thought yet) and attaching it to the tranny and covering the switch so it would be alot harder for the snow to get in and pack around it. Anybody else have any ideas to fix GM's royal #$%up? :mad: :mad: :mad:

[GM Smitty]

Are you sure they replaced your switch with the new and improved one. Seems alot of dealers are unaware of the new switch and are replacing a bad switch with another bad switch. New one is tan, old one black. Haven't heard of any new ones failing yet. I have the old one on my truck with the new one on the shelf ready to install when (if) it fails.

Josh

[mdrag]

heartbeatcanada,

What color was your replacement switch? The new NSBU switch is tan, and the old switch was black in color.

From other posts on this forum, it seems the 'old' NSBU switches are still being used by GM - both as warranty replacements and IIRC on 2003 trucks. A recent post by a 2003 owner indicated a black NSBU was installed on his truck.

It may be different north of the border.

[heartbeatcanada]

Ya i looked at it, and it was the tan one. I thought the same, maybe they didn't put the tan one on, but nope. The only thing i'm not sure on ,is if the last one had the shield on or not. Haven't had a chance to look at this one yet(too busy) but will be checking it out real soon. The shield better be in tact or theres gonna be a whole lot of snow hitten the fan. :eek:

[Bass_on_tap]

GM Smitty, interesting that you wrote:
"I have the old one on my truck with the new one on the shelf ready to install when (if) it fails."
I was thinking the same way. Have a good spare available if it fails. Then it dawned on me, when it fails, it will most likely fail away from home, the spare on the shelf will do me little go. I'm going to buy it and install it ASAP. It's a ticking time bomb. One less thing to worry about since it's already paid for anyway. IMO
Dave

[GM Smitty]

Bass on tap
Yeah, I know it will fail at the worst possible time (snowing, 10 degrees, 40 mph winds, etc.) I actually was thinking swapping it in earlier today. Maybe that job is moving up on the priority list now, especially in plowing season.

[SteveO]

heartbeatcanada,

I have installed 400 or more of the Updated NSBU's and I have only had maybe two or three come back.. Please read>>> Out of the 400+ I have installed 99% were replaced under the Allison (Freightliner/International) Recall..

If at all possible get the one that just came off your truck and look to see if there is physical damage around the selector shaft area.. More than likely the 1st replacement was damaged when it was installed.. The Tan switch is much better but they do fail like any other electrial part.. smile.gif

[DURA-MAX3]

what is a nsbu switch, i can't figure out what it stands for... Thanks

[mdrag]

DURA-MAX3

Neutral start back up switch, or in GM's terms PNP switch=Park neutral position switch.

There are a number of recent posts on the NSBU switch. Try a search in the Drivetrain forum for more..

mdrag

[ 01-08-2003: Message edited by: mdrag ]</p>

[DURA-MAX3]

Thanks mdrag, i was trying to figure out what it was and now i know. Is this a problem that is fixed on the tranny or taking the dash apart... Thanks in Advance...

[Black Dog]

The switch is attached to the transmission. When the switch is installed on the tranny, the gear selector shaft goes through the switch.

[mdrag]

DURA-MAX3,

I have a few pics of the old vs. new NSBU switch. Choose either link in my sig and choose the ALLISON 1000 NSBU album. The part# for the new switch is clearly visible on the box.

[HDLD]

I don't understand what the concern is over the NSBU switch. What stat's are we dealing with for Allison 1000's on 2500/3500 trucks? It would appear to me that very few failures have occurred under "normal" operation for us as opposed to, say, a delivery truck or someone who plows snow.

If I'm changing between Park/Drive/Reverse, about 30 times/week on average and at worse, moderate salt/slush, why would I want to be pro-active? If something goes wrong, won't it be while I'm cycling to another gear postion? Isn't it highly unlikely, this switch will fail as I'm driving down the highway?

I just don't understand why this is (at least for my driving) a disaster waiting to happen. If it is, then I'd gladly replace it immediatley.

[et]

HDLD,

To gain a better insight, you might want to do a search on the NSBU switch on this web site. Experiences occurred prior to you joining.

My NSBU switch partially failed while driving on I-84 while taking my wife to her cancer treatment. It was raining at the time. Once water got into the switch, my gear selector display went blank. I never stopped or changed gears until she was at the hospital.

Thanks to the information I had previously obtained on this board, I was able to get the newer NSBU for $45 from the Portland Allison Dealer while my wife was getting her treatment.

We are both retired and medical transportation is what I used my truck for last year although that is not what we had planned. During the year long odyssey, my "normal" driving style was 200 mile round trips to Portland, Oregon.

Since that time we have enjoyed pulling our 30 Airstream through the mountains of the Coastal, Cascade, Wallowa, and Steen Mountains in Oregon. Although out of season, I had no worries.

To me its a no brainer decision. No one is going to give you stastics only their personal experiences. By reading these experiences, you can make up your own mine. I did not totally loose my NSBU and I got it working again by drying it out and restarting the truck. $45 is a cheap insurance not only against the inconvience of a break down, but for the exposure of being dependent on people who most likey know less about our trucks than we do thanks to the TDP.

The switch fails because of moisture penetration not because of commercial or over usage. This can happen at any time. Allison has a recall because people depend on the Allison to make a living but GMC and Chevy does not. I changed mine so that a failure does not interfer with enjoying the better things in life.

[SteveO]

HDLD,

Your right, I see no need in going out and buying an Updated NSBU unless you need one.. I have seen very few fail on the pickups and far less on the Medium-Duty trucks.. The recall is more of a Good Will gesture than it's a safety hazard..

Like I have said before, the major failures were in FedEx and UPS and of those they were in a certain part of the country..

BTW: You can break the updated ones too.. The case is no tougher than the previous..

[drgracr]

I still have the original nsbu switch and if I understand this correctly, Allison has a recall on the switch but the General doesn't. So the new switch is customer pay from Allison and not covered under warranty.
Will someone with more knowledge on this please inform me better.

Thanks

[FirstDiesel]

If it fails under warranty then GM will replace it. They are just not issuing a recall for it.

[sswilliams]

I am kicking myself right now because I am not faithfully reading the boards.

Just got my truck back today from having the PNP switch replaced at the GM dealership. Parts and Labor: $213.75

Have been seeing the posts on the NSBU switch, but never really paid close attention.

Will DEFINITELY read the board thoroughly from now on!

[heartbeatcanada]

Never got a chance to get the old tan switch back to have a look at it. New one has the plastic shield installed. Hope this one lasts longer. :rolleyes: Went to the local Allison dealer last week and got fluid and filter, and out of curiosity i asked what the price was for the nsbu switch. He told me $96.00 canadian, i said i think i'll take one for a spare considering my warranty is almost up and the gm stealer wants $256.00 canadian. They couldn't beleive the mark up gm was pulling. Goes to show you, its worth the while going straight to the proper source, and they don't mind spending time with you, answering some questions about some extra horsepower and what they think should be done and so forth. :D

[HDLD]

et - I did a number of searches, perhaps I missed a few. Didn't go through all forums.

I'm not inclined to replace mine. Most of my driving is commuting to work and there is a dealer nearby at each end of the 55mi. journey and a few in between as well. I'll at least wait out the warranty period.

If I was in your situation, I probably would have opted for a replacement too.

BTW, how do you like your Airstream? I bet it pulls like a dream. Do you have a hensley-hitch or similar? I was drawn to 5er's with the ability to do so with the truck and the stability of towing but I've since learned that a properly setup hitch is a very similar experience. I don't think I'd want to go over 30' though! Enjoy...

[SteveO]

drgracr,

I work for an Allison Distributor and have been involved with the NSBU recall for over 1 year..

This is the skinny.. smile.gif

Allison found that the NSBU in certain applications (pickup/delivery) was failing at a higher rate than expected.. The reason&gt;&gt; The TCM looks at this switch a lot more than in any other application..
BTW: GM has used this SAME NSBU since 93 on it's pickups/Subs/s10s and they hold up very well...

Mid 2001 Allison came out with an improved NSBU (The Tan one w/Shield) that we installed on ALL UPS and Fedex trucks that have the 1000/2000-2400 Series Trans, at the same time we did a software update.. The update lowered the chance of a false code setting, and a bunch of other stuff that is not important..
Early last year Allison desided to include ALL OEMs that buy the transmission from them with the NSBU installed or sourced from Allison..
The OEMs I'm speaking of are Freightliner and International Truck/Bus..

If you know anything about the Medium-Duty vehicles, you will know that both Freightliner and International not only build Trucks they also build Chassis..

ALL other OEMs that have a 1000/2000-2400 buy (source) the NSBU directly from the manufacture, that's why the pickups are not involved in the "2002C1 NSBU Campaign"

Now back to what happens if one fails on a Pickup&gt;&gt;&gt;

If one fails on a pickup and the truck is still under warrenty the Dealership will replace it FREE of charge.. This does not necessarily mean the dealerhisp will install the updated NSBU..If they have the new one then it will be installed if they have the old one then it will be installed..

If the vehicle is out of warranty and it fails, then it's a customer pay.. It's up to you which one they install....

[technician]

Mine failed snow plowing @ 21300mi. I was able to get my dealer to change mine no questions under warranty. Now thanks to StevO I will check if tan or black. Do all replacments have plastic shield regardless of color or does the shield only come with the tans ? Also I plow commercialy and would like to know if dealer changed in a new black if you would advise that I change to a tan?
Thanks all dont't want to lose it in a snow storm again :rolleyes:
Chris,

[drgracr]

SteveO

Thanks, I now have a complete understading of this situation

[6.6L&94ImpalaSS]

I just had my second NSBU installed and the dealer said the new style is on back order, so they had to put the old style back on. The original switch lasted 63,000 miles and the second lasted 4,000 miles. I am thinking of going down to our local Allison dealer and checking to see if they have the new style in stock. I will buy it if I must.

The dealer did inform me they are getting alot of failures lately.

Mike

[hoot]

I wonder if a home grown vented shield that encloses the switch would be of help?

SteveO.. is it mostly moisture intrusion or it the switch poorly designed mechanically?

[BigAl]

I think the term is "robustness". The switch doesn't appear to be poorly designed so much as it is not robust enough to handle environmental conditions (water intrusion, for example) on a consistent basis.

P.S. As SteveO noted, this NSBU Switch has been used on Hydramatic trannys for quite some time. My guess is they chose to go with this switch on the 1000 Series so that connections on the production line were "common" between the 4L80E and the Allison..................less complexity on the line means less opportunity for someone to get parts crossed, mis-installed, etc.

[Buckman]

I just heard about a dealer installing the new/improved NSBU switch (tan) and the truck had the problem all over again in a fairly short time. Come to find out that the technician installed the new switch, but didn't install the shield. Sort of defeats the purpose, wouldn't you think? All the improvements in the world are useless if not installed properly. Just a heads up. By the way, a friend of mine mentioned that when installing the switch, it's a good idea to check the shaft for burrs prior to installation. It's possible that the end of the shaft could mushroom some from the nut being installed and tightened down on the previous switch. If so, a light hit with emery cloth or careful stroke of a file should take care of the problem. Sorry for rattling on so long, but thought this would be useful information.

Sure is nice to see that BigAl found his way back from the Dark Side.

:D

[hoot]

BigAl,

Exactly how does water get in?

[BigAl]

A sleeve inside the switch housing (the part that is pressed over the selector shaft) has to rotate inside the two halves of the switch housing when you select different gears. On the outside edge of both the front and back of this sleeve are seals. Water sometimes gets past those seals.

The felt washer on the back of the switch is to help prevent water intrusion on the backside, while the shield is intended to accomplish this on the front side.

Of course the question is, "What is the source of the water?" Since most of us aren't "swimming" our trucks (known as high water fording in military jargon), snow comes to mind, especially where it's deep enough to pack up into that area. That's were the felt pad and the shield are intended to help out. They probably aren't perfect, but a heck of an improvement from when there was nothing there.

Probably not all switches are replaced due to water intrusion. Some are replaced because they have actual electrical problems (bad connectors, contacts, etc.), some have cracked housings from chance encounters with road hazards, and some are replaced with NOTHING wrong with them.................just real easy to be replaced by a Technician who ain't got a clue what to do (unless you're SteveO, that is). smile.gif

Does that help??

[SteveO]

Hi guys,

Am I going to have to do an article about how to install an NSBU properly on the pickups?

It sure does look that way....

Give me some time....

[ChevysRus]

I think I had one fail a while back, but the dealer wrote up something else and it took 3 qts of fluid on the bill to fix it, The NSBU is "OUTSIDE" so no fluid should have been needed!!
Never did get a straight answer "it's under warranty and we took care of it, you don't need to know anything else" JEZ, have not been back since, but also no problems since so maybe they are right LOL

I understood (maybe incorrectly) that if the NSBU fails and you cut the truck off it will not re-start since the TCM can't detect if the Tranny is in park or neutral (hence words neutral safety switch)or is it the other way around, the truck will start in any gear when the switch fails?

If the latter, then not so bad as most of us can tell reverse from forward when we step on the pedal and if we go fast enough the tach will tell us what gear we are in and you can tap it up with the selector (maybe) so we should be able to make it home or to a dealer nearby to get it fixed.

But if it won't re-start because the NSBU doesn't know what gear it's in, then we need a tow truck!

So I guess my question (round about way to get an answer) is what is the worse case scenerio when the switch fails assuming you are putting along when it goes south?

Warmest Regards to those currently living where it's under 40 degrees ha ha ha

[BigAl]

ChevysRus,

Actually, if the NSBU wigs out on ya, it's OK so long as you're operating your truck in ambient temperatures LESS than 40 degrees. For those unfortunate souls operating in ambients OVER 40 degrees..........................well, you just better hope it ain't you!

Lets see, North Carolina.........sorry for your luck!!!

tongue.gif tongue.gif tongue.gif tongue.gif

[SteveO]

BigAl,

I Hate the cold.. Hate it.. We had 6-10" of snow Thursday morning, The temps are just now getting over the 32 mark.. The temps got down to 5 or 6 last night.. Did I tell you How much I Hate cold weather??????????????????????? smile.gif

BTW: I know where you work and will not hesitate to sic the Jolly Fat guy on ya.... smile.gif Just keep it up smile.gif ;)
----------------------------
Worst case senario&gt;&gt;&gt; The truck will not take range, or will only give you 3rd and Rev only.. Never had one not start because of a bad NSBU..
TCM P0708 is probably the most common code.. "Transmission Range Sensor Circuit High Input"...

[ChevysRus]

Hey Steve O and Big Al, I was under the truck yesterday doing some fluid changes and had a chance to take a good look at the NSBU switch. Would it be a good idea to spray that sucker with a silicone spray or a good die-electric to try and seal it from the harsh environment? Just a thought for added protection.

Stay Warm!

[SteveO]

ChevyRUS,

I don't know if that would help or hurt..

I have the black one on my truck and it's never gave me a lick of trouble.. I know of many with 100K and they are still on the original one..

[BigAl]

ChevysRus,

Conventional wisdom on putting grease/etc. on those kinds of parts is that the grease/etc. ATTRACTS dirt/grit/grime/rocks/leaves/little kids/etc. to the site in question, and that is generally a bad thing. If it were me, I'd pull the electrical connectors and put dielectric (sp?) grease on the INSIDE; reconnect, and make certain the outside was clean and dry.

As far as the selector lever end of the thing, I'd make certain I had the "tan" switch with the black shield properly installed, and leave it alone.

For sure I would not do anything overt to clean the area, like blasting it with a pressure washer.

P.S. Minus 8 on my car's temperature sensor this morning................. :(

[ChevysRus]

OK thanks Big Al and Steve O, I have the original NSBU and no trouble, just thinking about avoiding the problem.......so no more fording of streams or deep water puddles I suppose! LOL

I will take your advice and pull the connectors and treat them with a dielectric and then I think I will just put a big old condom over the whole thing and hope that protects it! ha ha ha

Thanks for all the great info as usual, I get more info from these pages in one afternoon than you can get sitting for hours at the dealer.

Also, I was in Indy on 12/6 at the big Performance Show downtown. It was not that cold then! LOL
Best Regards, ;) ;)