Chevy Kodiak 70 with 366

RGMartin

Well-known Member
I picked up a 92 chevy over the summer for a beater farm truck. I have been trying to sort out all its Gremlins to get it ready to haul some grain. Couple questions...

The 2 speed axle blows fuses any time you try to shift it. Is this likely just a wiring issue, or is there some inherent design flaw in the 2 speed which goes bad after 20 years?

Also the injected 366, I know on the Ford gassers in trucks you are supposed to "drive it like you stole it" in order to save the bottom end. Same issue with the Chevys? Anything to keep an eye on? it sounds good, starts good, seems to have OK power, but I'm sure that opinion will change once I put 250 bu of corn on it.
 
(quoted from post at 08:09:28 08/22/12) I picked up a 92 chevy over the summer for a beater farm truck. I have been trying to sort out all its Gremlins to get it ready to haul some grain. Couple questions...

The 2 speed axle blows fuses any time you try to shift it. Is this likely just a wiring issue, or is there some inherent design flaw in the 2 speed which goes bad after 20 years?

Also the injected 366, I know on the Ford gassers in trucks you are supposed to "drive it like you stole it" in order to save the bottom end. Same issue with the Chevys? Anything to keep an eye on? it sounds good, starts good, seems to have OK power, but I'm sure that opinion will change once I put 250 bu of corn on it.

The 366 is bullit proof as long as you keep the oil changed, on a regular basis. The two speed rear ends I'm familiar with were vacuum. If your blowing fuses. I would look at wiring (bare insulation, bad ground), linkage at the rear end, if applicable (corroded, dirty), switch/splitter on the shifter (corrosion, bare terminals/wires touching).
 
The engines are good. The fuel injected is a lot
better than the carb version but almost all 366's
whether it's in the bigger trucks or the 6.0 litre
in the pick ups, seem to have a problem with the
right side exhaust manifold cracking. I have a 366
fuel injected in a Top Kick, a 2000 Chev. 2500 and
used to have an older 6500 all with 366/6.0L
engines. Every one of them has a cracked manifold. I
was told it's good to change the fuel filter often.
 
On the two speed get it in high range and disconnect the switch and shift the gears ....I have a uncle that would disconnect the switch and take electrical tape and tape the swith in hi so you could not reconnect and move switch he would do to new trucks....one time when I was 16 he had a driver hired who reconnected switch took tape off and use the two speed he got it hung up between hi and low after we got it fixed he had me drive the truck home fired that driver....he told me later he had talked to the hired driver more than one time about the two speed ....so that is what i have allwayd done and never had one hang up between speeds
 
Do what you feel is right but to me it's pretty silly to throw out the baby with the bathwater like that... Just because you had ONE rear end hang up, they're ALL no good??? Doesn't make sense.

Especially since we're talking about a pretty new truck here. You'd think by the 1990's and 2000's they would have perfected the 2-speed rear end.
 
(quoted from post at 11:35:49 08/23/12) On the two speed get it in high range and disconnect the switch and shift the gears ....I have a uncle that would disconnect the switch and take electrical tape and tape the swith in hi so you could not reconnect and move switch he would do to new trucks....one time when I was 16 he had a driver hired who reconnected switch took tape off and use the two speed he got it hung up between hi and low after we got it fixed he had me drive the truck home fired that driver....he told me later he had talked to the hired driver more than one time about the two speed ....so that is what i have allwayd done and never had one hang up between speeds

I guess that advice might be okay if you live in flatland country, but around here those 2 speeds get lots of use. That's how you keep the truck rolling right along at a decent speed in the hills.
 
If it's a big block (aren't the newer ones in the pick-ups smallblocks), yes, slam your hand in the door on the way in, that way you are in the proper mood for driving it. Fertilizer truck I use for planting has one, rolls along pretty well, as long as you aren't trying to drag a seed tender. Usually only fill one 1500 gallon tank, but sometimes we fill both.
 
(quoted from post at 21:31:25 08/23/12) If it's a big block (aren't the newer ones in the pick-ups smallblocks), yes, slam your hand in the door on the way in, that way you are in the proper mood for driving it. Fertilizer truck I use for planting has one, rolls along pretty well, as long as you aren't trying to drag a seed tender. Usually only fill one 1500 gallon tank, but sometimes we fill both.

Looks like a 454, but supposedly the deck height is higher. Definitely not the pickup 6.0. I would have liked a diesel, but The whole truck was only a little more than it was worth for scrap. If I am only going to drive it a couple 1000 miles a year the price difference didn't make sense.

Not sure if it is currently stuck in high or low. Waiting on the door sticker to get back from the state so I can hit the road. The title only took 3 days. Been driving it around in the harvested oat fields. Seems like she is going to be screaming to get to 60 mph. Having the extra gears would be nice, some pretty big gaps as it is now, some big hills between home and where I plan to sell my crop this year. If I don't get it fixed it won't be the end of the world, it should still be better than dragging wagons with an open station tractor.
 
had more than one rear end hang up been around trucks my whole life owned trucks my whole adult life. I am 55 now. I am in nort Alabama we have mountains here ....just giving advice on a truck that will not be run everday he will have a lot less problems getting it in high and leaving it there
 
last 366 I had would top out around 70 you could hear 4 barrel sucking down the gas....you can remove the cover off the motor of the two speed on the axle and move the gear up or down from low to high or high to low and see if you are in hi or low
 
Block the wheels and get under there. Disconnect
the wires on the back side of the 2 speed motor and
then operate the switch on the gear lever. If it
doesn't blow the fuse then you know the problem is
in the 2 speed changer. The switch often goes bad
inside the changer. Last year a farmer brought one
to our shop and the changer was so worn out we
installed a whole new unit on the rear axle. It
shifted normally then.
 
(quoted from post at 12:29:26 08/26/12) Block the wheels and get under there. Disconnect
the wires on the back side of the 2 speed motor and
then operate the switch on the gear lever. If it
doesn't blow the fuse then you know the problem is
in the 2 speed changer. The switch often goes bad
inside the changer. Last year a farmer brought one
to our shop and the changer was so worn out we
installed a whole new unit on the rear axle. It
shifted normally then.


I am having one of those, "Well DUH, why didn't I think of that" moments.

Thanks for the troubleshooting advise.
 
a 20+ year old 366 is not near the same as the modern 6.0 engine. The 6.0 is from the "LS" family of engines. The 366 is a "big block family" engine. The 8.1 engine they made a few years ago although a good bit different than a 454 was still from the "big block" family. I have a truck with a 6.0 and one with a 8.1, they are vastly different engines.
 
Where I worked a few years ago, had a few of those Chevy's. I would check the wires where they go though the floor. Every time you shift them the wires have to bend. Also the New two speed electric controller (on the left of the rear end) Sucks. We changed them for the old ones with points instead of a circuit board. Just two bolts and the wires to change. Doesn't matter what brand of truck, all of them are the same. hope this helps Vic
 
They actually work a lot better if the unit gets regular shifting... A two speed that stick is one that's either been misused or never used.

If I had to live with one or the other I'd put it in low. You won't get there fast but at least you'll get there without taking the clutch out.

Rod
 
Blowing fuses... is probably a bare wire. Just trace it out and see. Otherwise a bad shifter. That shouldn't be too expensive either.

As far as the engine... I've run a 427 a little bit. It'll run with a DT466 provided you jamb your right foot to the floor and keep it there. The 366 will probably be a bit shy of that... but keep it wound up and it should make decent power.

Rod
 
I didn't say they were the same. They are the same displacement though and all the ones I've had had cracked exhaust manifolds.
 
I think it is funny that two engines that only share the displacement in common share the same generalized problem.
 
I drove here around some today... No go on the 2 speed. The truck isn't good enough to spring for a $500 shifter, maybe after the season if she proves her self. Seems to get out of its own way OK. HUGE gap between 3rd gear and 4th. Tried to shift 3-4 from a dead stop pulling a decent hill, she fell flat on her face. Seems like I would need to have it turning 3700-4000 rpm to make that one.

Only other issue I have found is a front brake caliper is hanging up a bit. Hoping that problem goes away on its own.
 
RG, The 366 is the 427 little brother. Just slightly smaller. It is a "Big Block" Has nothing in common with the 454 or the new 6.0L.!!!!
A 366 with a 5 speed and a 2 speed rear axle is truly a Bullet Proof set up and just about unstoppable.This trans & 2 speed set up is commonly call the "Working 4th & 5th" I have personally carried 42,000 of dry wheat on a C65 tandem w/ a 20 ft Midwest bed with 18 in high risers!!! The truck stood naked at 17,000 lbs I have come across the scales at 54,55,56 Thousand lbs!!!!!!!!!!!!!!!!!!!!!
Like some of the others have said, Keep the oil changed, oil the 2 speed unit on the axle. It is electrically operated It shouldn't blow fuses. disconnect the 2 speed unit and try it, that should narrow it down a bunch.
The 366 will run with most 427s just not use as much fuel!. The Holley carb can cause some problems of No Power, if the Power Valve are blown! In the panhandle where I ran the one I talked about 56K was a hell-uva load about 50/55mph was top with that kind of a load!
When all is in order the Governor kicks in at 72 MPH. Hold you Rt foot hard on the floor let the governor kick in, then, Let the engine breath ever so slightly, and put the pedal back on the floor and leave it, and away it will go. Ours would run 80 mph All Out or slightly better empty coming home from the elevator. Hope this helps.
Later,
John A.
 
(quoted from post at 00:33:54 09/14/12) In the panhandle where I ran the one I talked about 56K was a hell-uva load about 50/55mph was top with that kind of a load!
When all is in order the Governor kicks in at 72 MPH. Hold you Rt foot hard on the floor let the governor kick in, then, Let the engine breath ever so slightly, and put the pedal back on the floor and leave it, and away it will go. Ours would run 80 mph All Out or slightly better empty coming home from the elevator. Hope this helps.
Later,
John A.

Your roads must be a lot better than ours. I wouldn't dream of running it that fast around here. Too many twists, turns, hills, and Pittsburghers sightseeing. If I can average 35-40 MPH, hauling 15,000 I'll be happy. Don't want to hit anything or break the truck.
 
Now THAT is how you drive a 427. LOL.

We've got one in a fire truck here... most of the guys complain about it because the Ih with the 466-180 will walk all over it.
The 427 with Ruxel will out run it on the flat... and will pretty well pull with it on the hills IF you get her wound up and make use of the gears. Like you said... place right boot firmly on the floor and let her scream. She gonna pull hell then.
I kinda like running the old thing just to screw with the guys some days.

Rod
 
(quoted from post at 00:18:10 09/15/12) 3500-4000 is where you need to drive them anyway if you want any power from them...

Rod


Should I carry a shovel and a a couple bushel baskets to clean the parts off the road if she scatters?

At 4000 the engine is roaring like it is trying to climb out from under the hood.


SO just mash it and go...
 
Rod, True Story,,,,We finished up wheat in July one yr. Both trucks were running crappy. Had Both Holleys reworked w/ new Power Valves.
Fast forward to Corn harvest Mid October.
3:00 one afternoon we had moved to our East most Fields 10 miles away from our usual runs. As Luck would have it,I wound up sitting #4 in line @ the Elevator. #s 1'2'3 were our closest Neighbor over there... 3, Chevy twin-screw trucks with 20 ft beds, All w/ 427s and 2 5x4s, 1 13speed. They usually ran together and fast. Their #3 was last off the scales and a scant 2 minutes ahead of me as I sailed off the scales. As I cleared The North side of town they were only 1/4 mile ahead of me. Now our Fastest Tandem was a 72 C60, 366, 5speed and 2speed rear axle. Top on her was slightly over 80. I had a 10 mile run before we all took a side road to the west.
I poured the Coals to her, got her past the Governer, Lined out & Rt foot pushing the firewall forward!! I caught them by the The 5.5 mile line, passed them all by the 7 mile line in one sweep, cause I had a narrow bridge over a dry river bed,, had to contend with it, if I didn't, then had to climb a pretty good hill as I left that narrow bridge. Got to the top of the top of the hill in the lead, and made the turn and west just 150 yrds ahead as they made the turn. 5 miles west........
I parked in the turn row and had my tarp rolled back when they all three stopped and wanted to what we had done to our trucks Their trucks just wouldn't keep up with our smaller 366s. ...........just reworked carbs and knowing how to get all you can out of that engine. Namely getting past the governor, and plastering your Rt foot to the floor.. To this day I don't think they know how to get past the Governer!
Later,
John A.
 
An optional 454 could be ordered in the C70 back in 1979-80.... When it came time to replace a 454, a new 427 could be bolted into place.. same manifolds, water pump, etc.. 366 was often replaced with a 427 also.. Wasn't uncommon to have a few new 427 crate engines stored along the wall in one of my stalls..

Those medium duty (40-50-60-70 series) 454 truck engines were a different beast than the light duty (10-20-30 series) 454 engines.
 
The company I worked for ran 283,327 and 350s in the early 70's when I started working. Then in the early 80s they run 366,396 and 427s in Chevy & GMC tractors. Also in the early 80 they bought 7 L series Ford s powered by 370v4 gas engine. When those engines gave out they repowered them with Chevy 427s. They did try 429 Ford and 454 Chevy and found the 427 Chevy to be more reliable. Mid 80s on up they went to tractors powered with 3208 cats,IH DT466and different models of Cummins engines. The 38 years I worked for the company I liked the Chevy 366 and IH DT466 engines the best. The tractor I drove with the Chevy 366 was a stronger pulling engine than some of the 427s.
 

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