Hey everyone! My 1985 k20 4x4 6.2L (J code i think) is new to me and I'm starting from scratch learning diesel :) I have a couple questions and pics regarding my fuel filter(s). And a transmission question

1. I have the setup with one spin on filter on drivers side and a box filter on the passenger side.. The spin-on filter seems to have been completely disconnected from the gas supply and the box filter seems to be connected to the ip, but there is a fuel line coming from the bottom that is leaking fuel. The line from the bottom is not connected to anything, just hanging there. and the actual unit that the fuel filter connects to may be leaking as well..ALSO the vaccum connect on the left side of the unit is not connected at all.. Could anyone send me in the right direction as far where I connect that fuel line on the bottom and the vaccum line on the top left??

2. I guess my truck had a camper originally. It came with a 3 speed trans which is HORRIBLE! when I'm doing 65 I can't downshift on small uphills and it just "makes" it. Any suggestions as to regearing for less towing and more driving, or a new trans that will mesh ok with my 85 6.2 and give me some speed?? I know my 6.2 should be faster than it is, I think it has to do with this LOW LOW geared 3 speed trans.

Any help from you smart diesel guys would be so appreciated!
BTW my engine compartment is not usually this dirty, I went muddin yesterday :)

Thanks guys!

Jonny

the fitting on the bottom going no where is your water drain. seal on the box filter is probably shot. the other filter was probably an attempt to get around the leaks. a lot of people rip off the bax filter and replace it with a spin on.
gearing, would need to know what size tires you have to figure out what gears to go to

diaric,

since the box filter is connected to a bunch of wires (fuel heater) and all, how do they get around all that when they rip out the box filter? Do the spin on filters come with the heating units?
My tires are LT 285/75R16, but I plan on movin up a little bit, what would it be with the ones I have and the ones YOU have?

Thanks for your help!

The heating unit WIF light are not nessicary. Some disconnect them. Depends on how cold it is. You could swap it for a Racor setup. I have personally never had any issues with the box one. Older 6.2s had two spin ons. The TH400 has a detent cable that works really weird with diesels IIRC and most people disconnect it and downshift manaully. I believe my 83 was like that although I can't remember. Something is telling me that there was also a switch on the acc pedal on later ones. 6.2s are dogs powerwise so don't expect to be drag racing and Cummins' . It's a light duty pass class diesel. Treat good and it will give you good mileage and good fuel conomy. You can turn the IP up and drop a turbo on for some halfway decent power but again, no Dmax either.

....The spin-on filter seems to have been completely disconnected from the gas supply...

Good thing, too. Your truck doesn't run on gas.

This is just a friendly reminder to start calling it fuel and not gas, or diesel, or oil, or whatever. Just not gas. Get into the mindset of calling it gas, and you'll accidentally reach for the wrong pump handle and then you'll be in a world of hurt. Well, not really, but it won't be fun.

2. I guess my truck had a camper originally. It came with a 3 speed trans which is HORRIBLE! when I'm doing 65 I can't downshift on small uphills and it just "makes" it. Any suggestions as to regearing for less towing and more driving, or a new trans that will mesh ok with my 85 6.2 and give me some speed?? I know my 6.2 should be faster than it is, I think it has to do with this LOW LOW geared 3 speed trans.

The BEST trans for a non-turbo, non-towing 6.2 is probably an NV3500. Better gearing for driving around than the NV4500, and an overdrive gear to keep revs down and save fuel. You can find them behind some small block chevys and some V6's. Second best trans is NV4500, which also gives you an overdrive, but they're more expensive. You can find them behind BBCs and 6.5L diesels.

You probably have the TH400 trans, which is about as strong as an automatic transmission gets but you suffer for fuel economy. Switching to a 700R4 to stay automatic gives you a great 1st gear and an overdrive, if you aren't towing it'd be a worthwhile change.

I'd be willing to bet, by the sound of it, you have 4.10 gears. Moving to 3.73s would be significant, but not as much as 3.42. Just don't expect to tow 10,000 lbs w/ 3.42s. Hell, don't expect to tow 10k lbs with ANY setup at more than 45 MPH, and probably closer to -15 MPH uphill. Yes, that's a negative sign.

There's my four dollars and fifty cents (was originally going to be two cents, but this post got long).

i pulled around 12k at 75 mph. took a while to get there with 3.42's but i done did it and held it there except on the hills where i dropped outa OD down to 3rd and kept on chuggin. regearing is a PITA on a 4x4. you have 2 axles to do instead of just one. and one is a big enough PITA on its own. id grab up a NV4500 if i were you, just in case you wanted to grab a turbo down the road and im sure a turbo 6.2 will eat a NV3500 for breakfast with a side of eggs.

A 4l80e with a standalone works nicely too. That will be my solution to my CUCV.

If you are having trouble maintaining speed going up hills empty, chances are your injection pump is sick. Back in the day when these trucks had low miles on them and I saw one I wanted in a chevy lot, I would test drive and check top speed. If the truck would struggle to make 75 mph, I would take it back and tell them to put a pump on it and I will buy it. With a new pump, 90 plus mph and no problem with hills. Before you do anything however, change the fuel filter. The worst problem with 4.10's and no overdrive is engine noise. You could step up to 315/75/16's and that would give you the equivilent of 3.73 gearing.

One of the manual trannys mentioned, or an sm 465 manual 4spd (tho 1st is a granny gear and unuseable in daily driving), will be better all around for mileage and power than what you currently have. If you don't want to convert to a manual tranny, the simplest thing to do would be to get a 700r4 that has all the updated upgrades (fairly comprehensive list as these trannys without the upgrades are junk), but you wouldn't have to worry bout the electronics associated with the newer generation automatics and you would still have overdrive. Mind you, power is not something to expect from a 6.2 and automatics consume a rather large percentage of power. If it were my truck, I would go with the nv 4500. As said, gear changes in a 4X4 are no light undertaking, time and cost wise. If you are deadset on changing gears, the smart money would be to find a cheap junker truck with the ratio you want and swap the axles out. It sounds like a big job, but it really isn't, much simpler and faster than trying to regear or even set up a different tranny in the truck. Good luck.

You guys rock! Thank you for all the great information. I will look into all of these suggestions, I suppose I can go with a manual trans (which seems to be the popular suggestion)if that's what it takes to get this truck runnin at least normal speeds. I'm sure there is a good transmission with a good balance of street driveability and towing. I didn't know I had so many options! I only really want to tow maybe 6k max.
I will look into a new IP as well. Anyone know where I can find a high performance/heavy duty IP and injectors for straight swap? Should I go to 6.5 ip and injectors?
I don't know what I would do without this forum and you diesel pimps! Thanks again all!

Without boost a 6.5IP and Nozzles are a waste of money and a meltdown waiting to happen. Find a used banks setup. They are out there if you are patient. It will feel like a new truck.

get some short 6.2 injectors. those will work.

The heating unit WIF light are not nessicary. Some disconnect them. Depends on how cold it is. You could swap it for a Racor setup. I have personally never had any issues with the box one. Older 6.2s had two spin ons. The TH400 has a detent cable that works really weird with diesels IIRC and most people disconnect it and downshift manaully. I believe my 83 was like that although I can't remember. Something is telling me that there was also a switch on the acc pedal on later ones. 6.2s are dogs powerwise so don't expect to be drag racing and Cummins' . It's a light duty pass class diesel. Treat good and it will give you good mileage and good fuel conomy. You can turn the IP up and drop a turbo on for some halfway decent power but again, no Dmax either.

Hey, acesneights, what type of Racor setup would you suggest? The Racor website has so many, I don't want to underdo it or overpay :)

I'd have to look. I'm not running one myself but I run them on my class 8's and they are the bomb. Don't need nothing big. I'd even go as far as to call or email Racor and ask them.

i run a racor on my truck and that is the only filter i have. the part number of my filter is a r45s or the r45t will work also. i have no problems with mine.