2 vs 3 v- groove power steering pulley

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.

Sgt Gus

Full Access Member
Joined
Aug 2, 2023
Posts
352
Reaction score
542
Location
Texas
First Name
Mark
Truck Year
87
Truck Model
R20 3/4 ton
Engine Size
454ci/7.4L
So the '87 3/4 ton, 454 has a 3-groove power steering pulley. NOT coming off.
Will a 2-groove for the saginaw work and line up? The back v-grooves are approx 5.75" diameter. BThis truck was not using the front smaller v-groove 5.125 diameter?
Press on, remote reservoir, new one on the way.
Now I need to order a pulley.
 

ali_c20

Full Access Member
Joined
Sep 20, 2016
Posts
1,386
Reaction score
1,991
Location
Austria
First Name
Alexander
Truck Year
1974, 1979
Truck Model
C20, K5
Engine Size
350, 350

Sgt Gus

Full Access Member
Joined
Aug 2, 2023
Posts
352
Reaction score
542
Location
Texas
First Name
Mark
Truck Year
87
Truck Model
R20 3/4 ton
Engine Size
454ci/7.4L
Do you have a pulley puller tool ?

Which groove of the crank pulley was used ?

Rockauto shows a single and double groove pulley for your truck.

https://www.rockauto.com/en/moreinfo.php?pk=12729793&cc=1059982&pt=7381&jsn=990

https://www.rockauto.com/en/moreinfo.php?pk=12729797&cc=1059982&pt=7381&jsn=989

I would wait for the new pump, test mount and look how everything lines up.
Yes on puller, used PB and even torch. Tore the lip, once it started, no hope, but I tried.
Yes! Rockauto has. Pump was a 12541, but Lares didn't show a pulley on their website. But there it be on Rockauto. Called them just to verify. #159 They are very (Lares) helpful.
Thanks for your help! So much time researching crap...
 

Sgt Gus

Full Access Member
Joined
Aug 2, 2023
Posts
352
Reaction score
542
Location
Texas
First Name
Mark
Truck Year
87
Truck Model
R20 3/4 ton
Engine Size
454ci/7.4L
Ours was 3-groove but front smaller not used. So using the 2 v-groove pulley.
 

Attachments

  • 20250105_194207.jpg
    20250105_194207.jpg
    167.4 KB · Views: 15
  • 20250108_195824.jpg
    20250108_195824.jpg
    147.2 KB · Views: 13

75gmck25

Full Access Member
Joined
Oct 13, 2016
Posts
2,335
Reaction score
2,328
Location
Northern Virginia
First Name
Bruce
Truck Year
1975
Truck Model
K25 Camper Special TH350 NP203
Engine Size
5.7
Not sure it applies to every year, but on my ‘75 there are two choices for the PS belt. And I think that is why you have a 3 groove pulley.

The longer PS belt, which was the HD cooling option, goes around the PS, crankshaft and the water pump. If the alternator belt breaks, you will still have the PS belt driving the water pump. No overheating if the alternator belt is broken or slipping.

The shorter PS belt just goes around the crankshaft and the PS pulley.
 

AuroraGirl

Full Access Member
Joined
Sep 8, 2019
Posts
9,741
Reaction score
6,956
Location
Northern Wisconsin
First Name
Taylor
Truck Year
1978, 1980
Truck Model
K10, K25
Engine Size
400(?), 350
Not sure it applies to every year, but on my ‘75 there are two choices for the PS belt. And I think that is why you have a 3 groove pulley.

The longer PS belt, which was the HD cooling option, goes around the PS, crankshaft and the water pump. If the alternator belt breaks, you will still have the PS belt driving the water pump. No overheating if the alternator belt is broken or slipping.

The shorter PS belt just goes around the crankshaft and the PS pulley.
depending on engine and setup, the extra ps pump pulley slot powered some compressors (larger groove) or SMOG pumps (small groove)
 

Sgt Gus

Full Access Member
Joined
Aug 2, 2023
Posts
352
Reaction score
542
Location
Texas
First Name
Mark
Truck Year
87
Truck Model
R20 3/4 ton
Engine Size
454ci/7.4L
I bet for smog. The 87 has/had one on passenger side below the alternator. I believe 88 had two. One on each side.
Ours has a six groove serpentine from alternator, (smog), water pump to crank. Single v-groove from crank to power steering. 2nd single v-groove from crank, water pump, power steering, and AC compressor.
 
Last edited:

Sgt Gus

Full Access Member
Joined
Aug 2, 2023
Posts
352
Reaction score
542
Location
Texas
First Name
Mark
Truck Year
87
Truck Model
R20 3/4 ton
Engine Size
454ci/7.4L
Also, yesterday I realized I need the bracket off the old PS pump that the pulley didn't come off...PB, torch, Yada Yada. Got one bolt off, the 2nd...?! Well, "I fought the bolt and the hacksaw won"; repeat for triumphant song in my head! So not likely beable to repair old one for a spare.
 

ali_c20

Full Access Member
Joined
Sep 20, 2016
Posts
1,386
Reaction score
1,991
Location
Austria
First Name
Alexander
Truck Year
1974, 1979
Truck Model
C20, K5
Engine Size
350, 350
Also, yesterday I realized I need the bracket off the old PS pump that the pulley didn't come off...PB, torch, Yada Yada. Got one bolt off, the 2nd...?! Well, "I fought the bolt and the hacksaw won"; repeat for triumphant song in my head! So not likely beable to repair old one for a spare.
One stubborn bolt can mess up a lot....and drive one to the edge off insanity.
 

Sgt Gus

Full Access Member
Joined
Aug 2, 2023
Posts
352
Reaction score
542
Location
Texas
First Name
Mark
Truck Year
87
Truck Model
R20 3/4 ton
Engine Size
454ci/7.4L
Also figured out all the bolts are metric. M10x1.5, 20-25mm. Went to depot (while thinking about legomatic saying get a Irwin measuring tool) and used their on the wall dohicky to figure out and got two bolts. (Despite internet saying 3/8"-16) Cleaned and painted last night along with previous stud and bolt cap from the other. Those I couldn't remove until I just grabbed the air gun. Zip
Baking in the oven this morning. Still waiting on pressure side hose that keeps being delayed.
Staying on the happy side of sanity. ;)
 

Forum statistics

Threads
44,616
Posts
962,605
Members
37,155
Latest member
Troyport
Top