'78 K15 w/203 problems

[68post]

I just bought this truck yesterday after a short test drive and got a ride back to pick it up but then I didn't think it would make it home.

T-case is grinding popping and banging, literally sounds as if the chain is jumping teeth.
Has manual hubs which were unlocked. Seller claims that there was a sweet-spot for the range handle that prevented the minor grinding when he drove it and his "mechanic buddy" says that it "just needs adjusting" !! (this guy owned it less than one week).

It shows 66,xxx miles which I assume is 166,xxx miles and the case is high mileage.
1. Could be the high wear from mileage ?
2. Could be from the previous owner driving in 2 high too long without re-engaging high-lock to lube the rear bearing ?
3. Can't be an adjustment !
I'm going to try and reason a settlement with the seller as I am supposed to get him a new bottom section for his 16' wood garage door and install it (a job worth $375), but I've already paid the cash part of the agreement.

It's a High Sierra , pretty original but with a strong rebuilt 350/4bbl, th350, PS/PB/air, sea mist green, and has it's original ralley wheels on her. Not a rust bucket but it definitely has some.
Sorry but I don't know where my digital camera is lately.

I've already found a rebuilt 203 27 spline for about $125, but I aint paying for any labor.

[obijuan]

these are labor intensive trucks.
if youre going to be "paying labor" id sell it.

sounds like adjustment.
id lose the 203 all together and put a 205 in it.

[68post]

I just don't have the time or place to do it in this weather, I don't feel like I should be the one doing it either.
I've owned many trucks and wrenched allot in the last thirty five + years.
I want a 203 with a limited slip in both axles. Then I don't have to trust that my wife has unlocked the hubs or driven fifteen miles in low range. This truck will see limited use , just weekends and some daily use in the snowy season. "4 High" can be a poor-mans "auto 4wd".

[68post]

Originally Posted by obijuan

sounds like adjustment.

What adjustment would that be ? Shifter linkage ?

I was all over the shifter handle putting pressure on it in either direction and if I accidentally pushed it into neutral it was the only time it wasn't grinding !

[73chevy95]

those np203 are HEAVY!!! high suggest swappin to a 205

[68post]

Originally Posted by 73chevy95

those np203 are HEAVY!!! high suggest swappin to a 205

The only swap will be another 203, I have 2 other truck projects already and a '68 442 plus a Harley project too.

This was to be an inexpensive backup 4wd for my wife while her blazer goes back for warranty trans work and its 4wd pushbutton setup to be repaired too (another non-working 4wd, this makes three now ).

Wifey wasn't happy about the purchase and doesn't know now that it's not drivable !!

[LONGHAIR]

Originally Posted by 68post

I want a 203 with a limited slip in both axles. Then I don't have to trust that my wife has unlocked the hubs or driven fifteen miles in low range. This truck will see limited use , just weekends and some daily use in the snowy season. "4 High" can be a poor-mans "auto 4wd".

I see a few things here. First of all you stated that it has "manual hubs that are locked in". This hopefully means that it has had a conversion kit. This could be the source of the grinding noise. There is a small torrington bearing that is part of the kit, this acts as a spacer, but if it fails, the gears that it is "spacing apart" can make contact.

Next, especially for a wife's back-up", you really don't want a posi-traction unit in both axles. What is good for off-roading is not necessarily so good for snow/ice. Posi in the front would be unpredictable in low traction situations.

There is an adjustment, for the shifter itself, and I would bet it could use some attention, but I would check into the other things first.

Lastly....the comment about 4-high being like AWD, is only valid when the "full-time" is still active. Once it is "converted", that goes out the window, it is no different from any other 4 wheel drive. It is either locked-in or it's not, same as a 205 or a 208.

[bilfman]

I would say the 203 is shot. Lock out hubs is the give away. The 203 was designed with an oil pump and was meant to be continually spun. When the hubs are unlocked and the 4wd shifter is not engaged the pump does not spin and the back of the case gets no oil. Was common for lock out hub trucks to burn the 203 . If you have this set up one needs to engage the hubs or 4wd for a few mins every 100 miles or so. The other cheap fix is to extend the filler bung with some half inch pipe stock so you can fill the case with another couple inches of oil. The extra couple inches lets the case splash lube.

But in your case the damage sounds done. Also 203s do not take gear oil. They take a light oil such as 10-40w . Common for peeps to gear oil them and burn them up. Gear oil is too thick for the 203 pump to pump and you end up with the same rear case burn.

[68post]

Originally Posted by LONGHAIR

I see a few things here. First of all you stated that it has "manual hubs that are locked in". This hopefully means that it has had a conversion kit. This could be the source of the grinding noise. There is a small torrington bearing that is part of the kit, this acts as a spacer, but if it fails, the gears that it is "spacing apart" can make contact.

Next, especially for a wife's back-up", you really don't want a posi-traction unit in both axles. What is good for off-roading is not necessarily so good for snow/ice. Posi in the front would be unpredictable in low traction situations.

There is an adjustment, for the shifter itself, and I would bet it could use some attention, but I would check into the other things first.

Lastly....the comment about 4-high being like AWD, is only valid when the "full-time" is still active. Once it is "converted", that goes out the window, it is no different from any other 4 wheel drive. It is either locked-in or it's not, same as a 205 or a 208.

It must have a conversion in the transfer case because it drives with the hubs unlocked and not shifted into "lock" position.
Manual hubs were unlocked while I drove the truck (only a couple few miles at that). BUT, the seller ,I believe, may have driven the truck from northern IN to Indpls with the hubs locked-in and/or in "high lock". I asked him if he did so and he said yes he was in snow, I'm sure he drove on the interstate too. it's several hundred miles.

Torque-biasing differentials, no posi or locker in the front or rear axles (Detroit TrueTrac style). And she drives about 15 to 30 mph on snow, city streets only.
Once the Blazer is fixed she would drive it anyway , she loves the heated seats and it's Autotrac with pushbuttons - just her style.

I had a "real" Detroit locker installed in my cab'n chassis box truck because it needed the traction and something that it wouldn't break either. No , I didn't like the way it drove on ice.

I only want it to be back to full time four wheel drive with a 203 T-case !!
NO conversion.
I think that is probably how these 203's have become so maligned - from the mismanagement after conversion or not rebuilding high mileage units before they failed.

I know you don't know me, (after all I just found this great forum) but I do have forty years of doing most of my automotive work and have had at least a dozen trucks , a good half dozen 4 X 4's - but you'd be correct that I've not been into a transfer case , but I know of differences in the old style New Process cases ( 203,205,208). Learning more recently about 231 & 241.
I worked on my stockcar and my Harley.

I'm a GEARHEAD

I'll probably leave the hubs on since they are already there and my understanding is that can save some wear of the front knuckles , I know the front axles is live but not the stub axles when unlocked. I do know that without a conversion that I don't have to worry about engaging 4wd for 20 miles every 200 miles to be sure that the rear bearing in the 203 gets lube.

I could not find the "sweet-spot" with the transfer case shifter handle that the seller said he found while driving it - anywhere between neutral to high-lock !

Thanks for the help and all the replies so far, please keep'm coming.

[68post]

Originally Posted by bilfman

I would say the 203 is shot. Lock out hubs is the give away. The 203 was designed with an oil pump and was meant to be continually spun. When the hubs are unlocked and the 4wd shifter is not engaged the pump does not spin and the back of the case gets no oil. Was common for lock out hub trucks to burn the 203 . If you have this set up one needs to engage the hubs or 4wd for a few mins every 100 miles or so. The other cheap fix is to extend the filler bung with some half inch pipe stock so you can fill the case with another couple inches of oil. The extra couple inches lets the case splash lube.

But in your case the damage sounds done. Also 203s do not take gear oil. They take a light oil such as 10-40w . Common for peeps to gear oil them and burn them up. Gear oil is too thick for the 203 pump to pump and you end up with the same rear case burn.

I understand the conversion is only good for about 1 mpg gain, that isn't worth all the bs in my opinion.

[68post]

75w-85 gear oil is about the same viscosity as a heavy 30 weight motor oil, 80W-90 = a heavy weight 40 motor oil (15w-40 or even 20w-50).
But 80w-140 would be very heavy and equal a straight 70 or 80 weight motor oil.

I'm not convinced that gear oil was the true root of any problems in 203 's. I can see anything that is running on automatic transmission fluid that was originally engineered to run on heavier oil having wear problems tho'.
Chart here : http://www.bobistheoilguy.com/viscosity-charts/

[68post]

Originally Posted by LONGHAIR

There is a small torrington bearing that is part of the kit, this acts as a spacer, but if it fails, the gears that it is "spacing apart" can make contact.

Thanks, I wasn't aware , but that is the type of noise it is making.

[68post]

Problem solved. This truck is going back to the seller.

[68post]

OK, not happy at all about this transaction and neither is the seller. He lost-out on getting his garage door bottom section replaced - and lost money.
I'm missing a good classic (tight) shortbed 4X4 GMC w/air - and lost money also, and the second buyer is a cocky young SOB that tried to short him $200 from their original deal because I pulled the rug out from under him , but he shorted him $100 after all, plus he doesn't get a new 16' wood garage door bottom section installed - a$375 value with weatherstrip and tune-up/lube..

He got $1,700 . The K15 had a strong rebuilt 350/4bbl with 5,000 miles on it.

I'd have dealt with him somehow if it wasn't for the female equation that complicated the whole deal, and the fact that he was so broke that he couldn't have paid me if the other buyer wasn't there to meet us with cash.


Are there married men here that understand this problem ? (I had a rebuilt /unmodified 203 on the hook -= cheap) ???

[Zoomad75]

Married guy here...Just like trucks, the wife/gf/significant other vary from one to the next. I caught some grief buying my K5 sight unseen with a blown up 350 a good 10 years ago. I caught some more when I bought the 35's for it spending more money on the tires than I did to buy the K5 in the first place. I had to explain somethings, but I made sure the money spent wasn't taking away from the family budget.

Overall, we've been together 22 years (married for 17 of those) and she's become used to my automotive insanity. Given the same situation, I would have kept the truck. She would have been pissed when the truck had a major problem too, but the fix would have been relatively simple and done on the cheap in the driveway. I'm not a big fan of trading stuff for a reduced price as I've seen people get burned so I'm not sure what I would have done with that.

I know you didn't want to do the work even though you could. You might not want to hear this, but you probably won't find another one as clean or with a 5,000 mile fresh engine in it as you did in this one. If it wasn't to be a primary ride for the family, I would have parked it to the side and waited for a warmer day to slap the other one you found in. I'm saying that having helped out on a complete 4speed swap on Larry's K10 in a carport in the dead of winter back in Detroit. The cold sucked but it kind of made us move quicker to stay warm.

Besides, buying as is from a private individual you'd be hard pressed to make him pay the labor unless you had that nailed down in a sales contract. You got to expect problems on a 36 year old truck. It's probably why it was so cheap to begin with.

[68post]

Yep, but I didn't buy it for a project ! It was supposed to be "ready to run". I do have two other trucks (4WD) that are sitting ( & Harley, & 442), this was to replace her Blazer that is to go back under warranty for the trans and hopefully fix the
4WD also.
I liked this '78 as good and almost as much as my other two and more ( 2 great trucks), I was keeping it & decided to sell the other two.
Did I say it was factory air and all there ? Shortbed like my '94 ?

This hurts..,but it was at the wrong time too !

I have an '84 K2500 I was chasing before the K15 ,less $ and less truck in most ways, but it will be a work truck and when I sell my '90 V3500 3+3 I Can explain how its for the best