1971 K20- project just get driveable!!

[swamp rat]

My book said 120 on the U bolts also, the other book said 150 but that book also covers 73 and later so i think they goofed and omitted the 70-72 truck.

In my research i figure that there is no need for the shock to extend but maybe about 1" past the fully extended measurement on the truck because the springs cannot physically move any further, so for example if you buy a shock that extends to 26" but your extended dimension on the truck is 21" then your going to find that the body of the shock is so long that you loose a lot of compression travel. the shorter the shock extended length the shorter the body, the more compression travel you will get.

I think 5-6 compression would be great for my truck but i have a 4" lift. I called a couple places today (yesterday) before i went to work, both of them said for my truck and a 4" lift that my 4.25" front and 4.5 rear should be ok.. I'm still a little skeptical but the only real way to know exactly how much compression your system has is to compress the springs till they bottom, but how? even if you picked up one wheel with a forklift the spring is designed to support the vehicle so that won't work.

>>Golden question is just how much further (if any) can the axle go than the axle off ground (dangling) dimension? <<

This is something i didn't consider, i just assumed the spring would hold its shape but I suppose its possible there could be some kind force that might make it flex outward?of change but i cant imagine it being that much. I would guess about 1" would be ok.

[ryanroo]

Originally Posted by swamp rat

I think 5-6 compression would be great for my truck but i have a 4" lift. I called a couple places today (yesterday) before i went to work, both of them said for my truck and a 4" lift that my 4.25" front and 4.5 rear should be ok.. I'm still a little skeptical but the only real way to know exactly how much compression your system has is to compress the springs till they bottom, but how? even if you picked up one wheel with a forklift the spring is designed to support the vehicle so that won't work.

The appropriate method is to disassemble the spring. then make a spacer that accounts for the thickness of the spring minus the main leaf. then bolt the spacer to the main leaf with the center pin and re-install the springs. now you have an accurate mock up of the spring with a very low rate that will allow you to cycle the suspension as far as it could possibly ever go. that will allow you to get a correct shock length as well as required compression and extension number for the shock.

>>Golden question is just how much further (if any) can the axle go than the axle off ground (dangling) dimension? <<

the axle can be levered lower than its own weight will pull it down just free hanging. so, if you just lifted the truck and measured the droop odds are it would be less than the actual number that could happen with the leverage of the truck doing its thing. also you need to check the compression and the extension with the axle twisted. meaning one side stuffed and the other drooped. that will give you more accurate measurements. usually bump stops and limit straps need to be used with suspensions that are designed to be really flexable. stock and stockish lifted suspensions will limit themselves pretty well just on the design. but to be really safe you do need to test at full bump in case you end up catching a little unexpected air or something bad happens like a broken spring or something to that effect

This is something i didn't consider, i just assumed the spring would hold its shape but I suppose its possible there could be some kind force that might make it flex outward?of change but i cant imagine it being that much. I would guess about 1" would be ok.

leaf springs do pretty well with lateral location as long as the bushings are in good shape there will be some side to side motions just as an effect of the spring motion but it is mostly unnoticeable. crossover steering can make that feeling more apparent though

[Vintage Windmills]

I looked on Summit again tonight, and the next shorter set of skyjacker front shocks is for the stock setup, and are only 19" extended, which is about an inch short of what I need for my truck. Its a shame since the compressed length is only 12, which would give me a lot of compressive travel. It seems like they don't really have a shock for a kit anywhere between stock and 4 inches. Guess I will look at other brands or just hope the 3.75" of compressive is enough with the ones I have.

[swamp rat]

Originally Posted by Vintage Windmills

I looked on Summit again tonight, and the next shorter set of skyjacker front shocks is for the stock setup, and are only 19" extended, which is about an inch short of what I need for my truck. Its a shame since the compressed length is only 12, which would give me a lot of compressive travel. It seems like they don't really have a shock for a kit anywhere between stock and 4 inches. Guess I will look at other brands or just hope the 3.75" of compressive is enough with the ones I have.

Try looking at Bilstines, Allshocks.com or truckspring.com

I cant believe I'm gonna say this but if you go to the actual Fox shocks webpage they have a bunch of different sizes too, keep in mind my Fox shocks were specially valved for BDS and BDS only has "X" amount of sizes available with there valving for their kits. I considered going that route.

[Vintage Windmills]

Heres about the best I could find for fit:

http://www.summitracing.com/parts/ran-rs5001/overview/

13.25 compressed
21.125 extended

that allows 4.5 of compressive and over an inch below hanging position.

or these with about 4 of compr3ssive and a couple below hanging position:
http://www.summitracing.com/parts/tf...del/k20-pickup

http://www.summitracing.com/parts/tf...del/k20-pickup

How do the ranchos compare to tuff country to skyjackers?

[swamp rat]

I cant tell you how they compare, the last set of shocks i took off my truck were 90's technology hydraulic shocks, all the new gas charged shocks seem to have longer body's.

I can tell you Bilstines are one of the better names out there.

Also Skyjacker seems to have a great rep in their lift kits for a smooth ride so ya might look there.

For me it would be a crap shoot from what you posted, I may lean toward the Skyjacker soft ride shocks if the measurements worked out, Overall I'd probably just shoot for the most travel you can get. Sorry i cant be more help

[Vintage Windmills]

Originally Posted by swamp rat

I cant tell you how they compare, the last set of shocks i took off my truck were 90's technology hydraulic shocks, all the new gas charged shocks seem to have longer body's.

I can tell you Bilstines are one of the better names out there.

Also Skyjacker seems to have a great rep in their lift kits for a smooth ride so ya might look there.

For me it would be a crap shoot from what you posted, I may lean toward the Skyjacker soft ride shocks if the measurements worked out, Overall I'd probably just shoot for the most travel you can get.

I agree on all points. The bilsteins are pretty pricey for this work truck though.

It looks like I'm going to return the ones I have and go with the stock size skyjackers or tuff country. I did the math in a spreadsheet shown below. The 1000 lbs plow will pull the front down another inch and also I may see some sag over time with the new springs?

So the stock sizes will give me 5" or more and the tuff country will have 3" of extension and the skyjackers only about 1.5", and more with the plow on. I'm thinking the tuff country fit the best, hope they ride nice with the skyjacker springs. The bump stops are about 4.5" from the resting spot, so I want at least that much compressive travel.



Oh, and I put money down on this truck below. Previous owner is going to pull the nv4500 though before I can get it. Not sure when or which truck the 6bt will go into, but probably this ochre K20! more reason to have more compressive travel. I estimate the cummins will squat it by 0.5" more than the SBC. Spring rates are 550lbs/per inch and I believe that's per spring.


I hope its a D60 and not a D61 (he said it was pretty tall geared) but either way, the price was right.

Yanked apart the rear axle today and started on brake conversion


Stupid caliper plate diameter is too small by about 1/8" wont go over shoulder:

[swamp rat]

Let us know how the new shocks work out.

What brand is that plate? Here's a couple more.
http://diy4x.com/cart/index.php?rout...&product_id=35
http://www.ruffstuffspecialties.com/...g/EHO5272.html

Is that your blue truck in the background? K20? C20?

[Vintage Windmills]

Yep, the blue truck in the background is my 1st K20. Its the project that this truck is distracting me from. Plan is to do nut and bolt frame off on that one. There is a build thread in my sig for that.

Plates are NW fabworks. I ground one out tonight with the die grinder. Took about 20 mins and now it fits good.

Also, working on spraying undercoating on the backsides of the bumpers, then I will paint the outsides semi gloss white.

I got the drums off and the bearing races out of the rear hubs. now its time to clean, paint, and put the new races in.

[swamp rat]

Originally Posted by Vintage Windmills

Yep, the blue truck in the background is my 1st K20. Its the project that this truck is distracting me from. Plan is to do nut and bolt frame off on that one. There is a build thread in my sig for that.

Plates are NW fabworks. I ground one out tonight with the die grinder. Took about 20 mins and now it fits good.

Also, working on spraying undercoating on the backsides of the bumpers, then I will paint the outsides semi gloss white.

I got the drums off and the bearing races out of the rear hubs. now its time to clean, paint, and put the new races in.

Don't forget to pack the hub bearings with grease even tho its lubed by the gear oil. Thanks for the info on the brackets too!

[Vintage Windmills]

i was wondering what the factory assembly manual said about packing the bearings. i was planning on it but now that you mention it, dont see why it would be required. on the other hand, i dont think it would hurt anything either so why not.

[Ol Blue K20]

I don't know what the manual says but I was taught by my mentor to pack them. His theory was you are sure they are lubed until the gear oil works through them...

[swamp rat]

Originally Posted by Vintage Windmills

i was wondering what the factory assembly manual said about packing the bearings. i was planning on it but now that you mention it, dont see why it would be required. on the other hand, i dont think it would hurt anything either so why not.

Yes the manual does say to use a high melting point grease, chapter 4-20, this is the downloadable factory service manual i downloaded from here on the forum

I look at it like i would never rebuild an engine without lube nor any bearings, even on a manual tranny i would use some assy lube. Go look at where your fill plug is in relation to the hubs, its actually below the hub level, the hubs get gear lube by the lube being flung around and cornering ect. So how far down the road would you get before the bearings get properly lubricated? The grease will eventually dissolve into the gear lube.

Here's another thread for reference:
http://67-72chevytrucks.com/vboard/s...d.php?t=475710

[Vintage Windmills]

Originally Posted by swamp rat

Yes the manual does say to use a high melting point grease, chapter 4-20, this is the downloadable factory service manual i downloaded from here on the forum

I look at it like i would never rebuild an engine without lube nor any bearings, even on a manual tranny i would use some assy lube. Go look at where your fill plug is in relation to the hubs, its actually below the hub level, the hubs get gear lube by the lube being flung around and cornering ect. So how far down the road would you get before the bearings get properly lubricated? The grease will eventually dissolve into the gear lube.

Here's another thread for reference:
http://67-72chevytrucks.com/vboard/s...d.php?t=475710

Just take a hard left and then a hard right

Thanks for the info from the manual. If not using grease, I'd still put assembly lube or gear lube on them. The question is whether to pack or just dip in lube. Still thinking I will just pakc since its not a big deal

[Vintage Windmills]

Spent a lot of time this weekend getting the rear axle components cleaned up and painted.
Got the new rotors (still masked from painting) mounted on refreshened hubs. I achieved a workout hammering the new studs in!


Finished grinding the caliper mounting plates. Trying to figure out how to mount them so the caliper is in the best position.

Option 1: more protected from debris and getting hit.





Option 2: weird positioning but good angle for ebrake and bleeder.





Think option 1 makes more sense.

Oh, and bumper backsides undercoated. Figured paint would just get chipped off, I can always shoot more of this on when it wears down.

[swamp rat]

A thread that may help?
http://67-72chevytrucks.com/vboard/s...9&postcount=15

I found this picture doing a Google search, forgive the non Chevy part.
http://moparforums.com/forums/93670-post19.html

Great progress!

[glimmertwin01]

Being you are up in MN. I see you got a ton of snow in the last week or so.I guess she isnt plowing much snow yet.? I feel your pain... the 68 K1500 I was hoping to use to plow with isnt any where near ready, so I will continue to use the 86 CUCV M1008 i snagged a yr ago... she plows like a beast ..and burns oil! I always find that my ..."just get it working" plans always morph into much more... My first truck is still packed away in my garage Its a 68 K20 4 speed 292 truck.

[Dieselwrencher]

Whenever I rebuild a rear end or have the hubs off I always fill each hub with lube before installing the hub and fill the diff with lube, then jack one side of the truck way up and let the fluid fill the hub. Then I repete for the opposite side. I do this one more time with less angle after the first 2 to help make sure each hub should have the same amount in them. I used to pack the bearings but a lot of wheel bearing grease will gum up these newer type semi synthetic gear lubes and a lot of the stuff I work on require it.

[Vintage Windmills]

Originally Posted by glimmertwin01

Being you are up in MN. I see you got a ton of snow in the last week or so.I guess she isnt plowing much snow yet.? I feel your pain... the 68 K1500 I was hoping to use to plow with isnt any where near ready, so I will continue to use the 86 CUCV M1008 i snagged a yr ago... she plows like a beast ..and burns oil! I always find that my ..."just get it working" plans always morph into much more... My first truck is still packed away in my garage Its a 68 K20 4 speed 292 truck.

Seems to be the way things go! although i had to change the springs anyway with the heavy front plow and the eaton drums werent feasible to replace. we havent gotten hit too hard yet this year right where i am, probably 5 inches so far. north of here got dumped on!

Originally Posted by swamp rat

A thread that may help?
http://67-72chevytrucks.com/vboard/s...9&postcount=15

I found this picture doing a Google search, forgive the non Chevy part.
http://moparforums.com/forums/93670-post19.html

Great progress!

thanks for the links. the dodge one is installed wrong, hes got the right caliper on the left side and the bleeder on the bottom. the other thread is a good one, but he has an extra set of holes in mounting plate. i suppose i could add some to mine.

after no luck finding parking brake lever brackets, i have a new set of calipes on the way from speedway with them included. I can then mock it up agqin this weekeend and see what angle works for the park brake and drill additional holes in the plate if necessary. i hope these calipers provide enough stopping power, thinking maybe i should have just played around with a set of big ones, like off a 2001 to 2004 2500hd. course that would involve custom mounting probably.

now i need to see about retuning the other caliper set to rock auto and the shcoks to summit

Originally Posted by Dieselwrencher

Whenever I rebuild a rear end or have the hubs off I always fill each hub with lube before installing the hub and fill the diff with lube, then jack one side of the truck way up and let the fluid fill the hub. Then I repete for the opposite side. I do this one more time with less angle after the first 2 to help make sure each hub should have the same amount in them. I used to pack the bearings but a lot of wheel bearing grease will gum up these newer type semi synthetic gear lubes and a lot of the stuff I work on require it.

good to hear another method

[glimmertwin01]

personally I dont mind rear drums... and if its a semi beater / plow rig to get running.. leave the Drums, and use em on one of the trucks u want to make mint.

[Dieselwrencher]

I think the biggest reason to get rid of the drums is due to the lack of parts available for theses rear axles.

[Vintage Windmills]

Originally Posted by Dieselwrencher

I think the biggest reason to get rid of the drums is due to the lack of parts available for theses rear axles.

yep, the problem is there were at least two brake sizes in these. Mine is 71 only narrow (2 inch) config and drums couldn't be found. I was finding some listed for the wider (2.5 inch) 72 style.

[erikoj]

very interesting to me as I just purchased a califonia K 10 1972 with the same ochre color scheme and the parchment white interior. Mine is in a little better shape ! I plowed snow for 10 years (45 driveways) with a 1966 k10 . I miss that truck , it was a workhorse with a 292 cu inch 6. keep up the good work, looks like you are an experienced mechanic. I will be using my truck daily in my building business. I just can't let it sit !!

[Vintage Windmills]

So the good news is I got the new calipers from speedway's garage sale and the brackets look good for the parking brake. Bad news is these calipers are much smaller than the Eldorado or K20 fronts so they are of no use to me. I will take the brackets off and try and sell on ebay or something.

The brackets need to be trimmed a little to clear the mounting bolt. Also one caliper wasn't drilled for mounting these, so I drilled and tapped it.


With the new parking brake brackets on the caliper for a mock up:



I determined the best position for parking brake and bleeding is at the 3:00 position. That meant I had to drill and extra set of holes in the plate. Plate was hard steel or high grade steel so I had to go slow and was only able to make it with this nice cutting fluid. Love this stuff:


Got the bearings installed, and oil seals, and prelubed with semi synthetic gear lube.


Hubs are now on the truck, as are the dust shields and plates. Need to torque the nuts and install lock rings to preload the bearings. Looks like I should torque inner nuts to 55 ft lbs, back them off 1/4 turn, bend short tab on lock ring in, install outer nut and torque to 175, then bend long tab over outer nut.

Got the bumpers painted!

[hgs_notes]

Almost there. Might have it ready to go by the time I stop by for a visit. I need to get a good look at those rear disks.