83 K10. 6" lift. Question

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

83customdeluxe

Junior Member
Joined
May 24, 2023
Posts
3
Reaction score
0
Location
Montana
First Name
Logan
Truck Year
1983
Truck Model
C10/K10
Engine Size
305
I installed a 6in lift. My drive line angles are terrible since I didn't shim my axles. What degree of shims would I need? & should I drop the transfer case as well? I was told I could destroy my transmission if I don't. This is my daily driver, I just drive a few blocks a day no crazy off roading
 

Attachments

  • PXL_20230817_161904416.jpg
    PXL_20230817_161904416.jpg
    190.7 KB · Views: 164
  • PXL_20230817_161851874.MP.jpg
    PXL_20230817_161851874.MP.jpg
    160.6 KB · Views: 127
  • PXL_20230817_161720432.MP.jpg
    PXL_20230817_161720432.MP.jpg
    126.8 KB · Views: 112
  • PXL_20230817_161633820.jpg
    PXL_20230817_161633820.jpg
    199.5 KB · Views: 118
  • PXL_20230817_161703084.MP.jpg
    PXL_20230817_161703084.MP.jpg
    138.3 KB · Views: 126

Strick

Full Access Member
Joined
Nov 25, 2020
Posts
1,356
Reaction score
3,319
Location
Dunn, NC
First Name
Harold
Truck Year
1979
Truck Model
C20 Crew
Engine Size
350
The rear block kit should have a pinion wedge made into it. You may could get a 4 degree shim and add to the spring pack but the obvious problem is the necessity of lengthening the rear driveshaft. The way the yoke is pulled out of the transfer case tail housing I'd suspect it would be no time before either the rear bearing in the case or the yoke itself to break. There are companies that make a spacer for the front shaft IF you are having the same issues there as well.
I usually take the spacer from the crossmember bolts and sandwich between the frame and crossmember as a means to drop the unit about 3/4 inch or so. Be mindful about the engine fan hitting the shroud when doing this though. I've had trucks that I had to "adjust" at the radiator because the trans/case unit was dropped.

HS
 

83customdeluxe

Junior Member
Joined
May 24, 2023
Posts
3
Reaction score
0
Location
Montana
First Name
Logan
Truck Year
1983
Truck Model
C10/K10
Engine Size
305
So I can just buy blocks that are already shimmed? Sounds easier than trying to wedge one in. I don't even like the blocks but I didn't have $800 to spend on already lifted rear springs. Think I'll save for that after I get my clutch replaced. What is the company name that makes the spacers? How would I lengthen my drive line? I'm not sure where the cross member is & I'd rather not drop the transfer case. I definitely don't wanna break anything so I'll probably stop driving it till I fix the issue with the **** hanging out, I added a pic of the front drive line to the post
 

Bextreme04

Full Access Member
Joined
May 13, 2019
Posts
4,439
Reaction score
5,581
Location
Oregon
First Name
Eric
Truck Year
1980
Truck Model
K25
Engine Size
350-4bbl
I installed a 6in lift. My drive line angles are terrible since I didn't shim my axles. What degree of shims would I need? & should I drop the transfer case as well? I was told I could destroy my transmission if I don't. This is my daily driver, I just drive a few blocks a day no crazy off roading
You lifted it with blocks, so you never changed the driveline angles. If you drop the T-case, you will be changing the angle of the transfercase drive side and would then need to shim the rear axle. Basically, if you extend a straight line out from the transfer case and a straight line out from the front of the pinion on the axle, the two lines should be parallel. The problem you are going to run into with a big lift with very little driveshaft length, is that the angle needed is going to be very large. You want to keep the operating angles at 3 degrees or less, but that is almost impossible on a lifted truck. Heres a calculator tool that spicer has. It also has driveshaft diagrams and tables showing operating angles and good guidance on what you should be looking for. You can get an angle finder from amazon or harbor freight to plug in the values for the calculator.

https://spicerparts.com/calculators/driveline-operating-angle-calculator#more
 

Bextreme04

Full Access Member
Joined
May 13, 2019
Posts
4,439
Reaction score
5,581
Location
Oregon
First Name
Eric
Truck Year
1980
Truck Model
K25
Engine Size
350-4bbl
The big problem you have is that the slip yoke is not inside the T-case enough anymore. It is unsupported and is flopping around against the bushing. It will wear it out and eventually snap your tailhousing off the T-case. Thats why you see all that fluid thrown around near the t-case tailhousing. You can just get your current driveshaft extended at any driveshaft or offroading shop. It's pretty common. General rule of thumb for most driveshaft lengths is to measure the distance is to have the rear axle at the fully compressed height, then disconnect the current shaft from the axle, bottom the slip yoke out in the tailshaft, then pull it out another 1/2-1". Once it is bottomed out and then pulled back out that 1/2"-1", measure how much longer it needs to be to fit back in the axle. Tell the driveline shop to extend it that much and rebalance... done.
 

83customdeluxe

Junior Member
Joined
May 24, 2023
Posts
3
Reaction score
0
Location
Montana
First Name
Logan
Truck Year
1983
Truck Model
C10/K10
Engine Size
305
Damn. I shouldn't have lifted my truck. That sounds expensive & I would have to get my truck hauled over an hour to get to a drive line shop. If I sold this truck as is what do you think I could get for it? I definitely should have got pre lifted springs
 

Bextreme04

Full Access Member
Joined
May 13, 2019
Posts
4,439
Reaction score
5,581
Location
Oregon
First Name
Eric
Truck Year
1980
Truck Model
K25
Engine Size
350-4bbl
Damn. I shouldn't have lifted my truck. That sounds expensive & I would have to get my truck hauled over an hour to get to a drive line shop. If I sold this truck as is what do you think I could get for it? I definitely should have got pre lifted springs
I think you are still misunderstanding something here...

Lifting it with a spring might actually have been worse. Using a block in the rear means that the driveline orientation did not change at all. Had the lift springs changed the geometry, and you still lifted it the same amount, you would have needed to use wedges or drop the transfer case in order to get them back in alignment. Then, you still would have to have solved the problem of the 6" lift making your driveline be too short.

Different springs or moving the spring mounting points will change the geometry. The height of the lift makes the distance the driveshaft needs to be increase. Generally, a 4" lift is considered the absolute biggest lift you can go without needing to lengthen the driveshaft.
 

Craig 85

Full Access Member
Joined
Jan 25, 2017
Posts
3,917
Reaction score
4,116
Location
Nashville, TN
First Name
Craig
Truck Year
1985
Truck Model
K30 SRW
Engine Size
454/TH-400/NP205
I can't tell too much in the front, but it seems your front spring are short for some reason. The shackles look pulled forward instead of being close to vertical. Could just be optics.

You could always get a shorter block in the rear with a taper to lower it and in the front take out a leaf or two depending how many are in there. It may get you down to a 4" lift, but would be a lot less headaches.
 

Latest posts

Forum statistics

Threads
44,185
Posts
951,089
Members
36,310
Latest member
BLAKMAX
Top