stock rear end gears - The 1947 - Present Chevrolet & GMC Truck Message Board Network

messed up c-10 · 07-02-2003, 01:05 PM

Were the gears all the same no matter what engine or trans. combo a truck came with?

Prerunner1982 · 07-02-2003, 01:08 PM

no, but apparently from what i have seen the most common were the 3.08s atleast in the late 70s-80s trucks...

messed up c-10 · 07-02-2003, 01:16 PM

Anyone know what an 84 with a 250 inline six and a four speed would have had in it?

gldevall · 07-02-2003, 01:22 PM

I've got an 86 and it had the 4.3 V6 with 400 TH and I have 2.73's.

messed up c-10 · 07-02-2003, 01:29 PM

Did C-10s and K-10s have the same rear axle? If so I might have some low gears. http://www.chuckschevytruckpages.com/73-87specs.html Down at the bottom it lists Axle Ratios for K10s.

messed up c-10 · 07-02-2003, 04:45 PM

Now I'm confused. The RPO codes I got off of one site doesn't list my rear axle but Mike's site does and it says that I have
GQ1: REAR AXLE - STANDARD
does that mean I have 2.73's? If I have 2.73's then my truck must have gotten very good mileage with an I-6 and 700-R4. Also for my orginal trans. one site said 700-R4 and Mike's said
MX0: MERCHANDISING OPTION ONLY-DO NOT CATALOG
Anyone know a good way to see what kind of gears you have without having to take off the differential cover?

SCOTI · 07-02-2003, 05:55 PM

The earlier 67-72's w/6cyl usually needed a little more gear to get them going (as do most smaller displacement vehicles). Both of the 6cyl's I own came w/3.73's.

Of course things changed in 73, but I would still guess 6cyl's came w/@ least 3.42's.

Prerunner1982 · 07-02-2003, 07:08 PM

gq1 i believe is the 3.07s or 3.08s atleast thats what mine says i have.

83C · 07-02-2003, 09:10 PM

My truck came from factory with a I-6 and a 4-speed with the GQ1 rearend. I took the differential cover off and counted the teeth and it have 2.73 gears.

Prerunner1982 · 07-02-2003, 09:23 PM

ok i am stupid. hence the user text!

SCOTI · 07-02-2003, 09:31 PM

Prerunner, I have some buddies here in DFW that are in a band called . . .... The VillageIdiots.

Check out their site @ IdiotsVillage.com

**swervin ervin** · 07-02-2003, 10:16 PM

GQ1 just means it's a non posi rear. G80 is for posi. Standard means what was standard for the year. It gets confusing sometimes.

Look on the front of the passenger side axle tube about 3 - 5 inches from the carrier. See if there is an RPO code stamped there. I'm pretty sure if there is a code, the first three letters will tell you what gear it came stock with. Let me know if you find a code and what the first three letters are. I also need to know what rear brakes you have. 11 x 2, or 11 x 2.75.

gldevall · 07-02-2003, 10:16 PM

GU2 is 2.73

gldevall · 07-02-2003, 10:21 PM

Found it.

RPO CODES (CHEVY). ... RATIO GM3 : AXLE REAR, 3.45 RATIO GM8 : AXLE REAR,... 2.56 RATIO GQ1 : AXLE, STD ... ENGINE, GAS, 6 CYL, 2.8L, 2BBL, V6, 60 DEG, TRUCK LR6 : ENGINE

**swervin ervin** · 07-02-2003, 10:43 PM

Uhh, I don't know where you got this from, but our trucks never came with a 2.8 V6, and especially a 60 deg one.

My 85 was a GQ1, and it came with 2.73's, which are RPO code GU2. GQ1 only means non posi. Look at this sheet that was in the dash of my truck when I bought it.

http://www.73-87.com/photos/old/build_sheet.jpg

ElGracho · 07-02-2003, 10:56 PM

I figured KIILew would have been in on this one by now, but GQ1 doesn't mean non posi or any specific axle ratio. It means "Standard Axle Ratio" which you can look up in a table for your GVW, your engine, your trans, and your body style (Long bed, short bed, blazer, etc.)

For this case, from my 84 Light Duty Chevy Trucks Preliminary Data Book, from the power teams chart on page 78: A 1984 C-10 with a 4900-5600 # GVW, the LE3 4.1l 6 cyl and the MM4 4-sp would have 2.73 gears as its GQ1 option. With the MM7 4-sp, it would have 3.08's. With a 6100# GVW and the MM4 it would have 3.08, and MM7 it would have 3.42.

In this case, MM7 is the 4 speed with overdrive and the MM4 is the 4 speed without.

Mind you all of these are C10's even with 4 different GVW's. The C20, K10, K20 etc. are all in different tables.

On the other hand, the optional axle ratios are fairly easy to decode. GU2 = 2.73, GU4 = 3.08, GU6 = 3.42, GT4 = 3.73, GT5 = 4.10, HC4 = 4.56. As long as you don't have the 'standard' ratio for your particular combo, you can pretty easily figure out what your truck had originally. If you do have the standard ratio, you need a little more information and a table corresponding to your year to figure it out.

**swervin ervin** · 07-02-2003, 11:36 PM

Thanks for clearing the GQ1 thing up. I stand corrected.

messed up c-10 · 07-03-2003, 12:35 AM

ok guys heres my RPO sheet.

TIMSPEED · 07-03-2003, 01:11 AM

Hmm..how would I figure out what mine came with? I THINK they're 4.10's (from RPM). But how can I be sure? I didn't see ANY markings on the passenger side axle tube. I DID see some #'s on the actual carrier. Like, #389xxx..

ElGracho · 07-03-2003, 01:19 AM

Quote:

Originally posted by messed up c-10
ok guys heres my RPO sheet.

With MX0 and LE3 in an 84 C10, your truck originally had 3.08 gears with the GQ1 code.

gldevall · 07-03-2003, 12:21 PM

Quote:

Originally posted by swervin ervin
Uhh, I don't know where you got this from, but our trucks never came with a 2.8 V6, and especially a 60 deg one.

My 85 was a GQ1, and it came with 2.73's, which are RPO code GU2. GQ1 only means non posi. Look at this sheet that was in the dash of my truck when I bought it.

http://www.73-87.com/photos/old/build_sheet.jpg

Guess I should have read it better before I posted it. I found that through searching on Yahoo. Must have been out of an S-10.

07-02-2003, 01:05 PM	#1
messed up c-10 RHCP afficianado Join Date: Oct 2002 Location: McLoud, OK Posts: 789	stock rear end gears Were the gears all the same no matter what engine or trans. combo a truck came with? __________________ ~Ryan~ 89 S-10 Blazer with a 4.3L 96 Ford Crown Vic P71 4.6L V8. This car rocks. Here are some links to some good music. Jack Johnson Donavon Frankenreiter

07-02-2003, 01:08 PM	#2
Prerunner1982 Registered User Join Date: Oct 2002 Location: Edmond, OK Posts: 5,904	no, but apparently from what i have seen the most common were the 3.08s atleast in the late 70s-80s trucks... __________________ Jon 1982 Chevy Silverado 350/th350.... RETIRED 1993 Jeep XJ 2 door(Cherokee) 4wd 4.0ltr/AX-15 (5spd)/NP231 .... Oklahoma Roll Call

07-02-2003, 01:22 PM	#4
gldevall Registered User Join Date: Mar 2003 Location: Walker, LA Posts: 2,925	I've got an 86 and it had the 4.3 V6 with 400 TH and I have 2.73's. __________________ Gary -1986 SWB: lowered 4/6, SOLD!!! -Best 1/4 mile: 14.51 @ 91.01 MPH -2001 Pewter Tahoe, billet grill, Corsa Sport Cat-back, K&N FIPK SOLD!!! -2004 Z-71 Extended cab with a flowmaster, BDS 6.5", 3" BL, 35x12.5x18 Trail Grapplers on Pro-Comp 18x9 wheels

07-02-2003, 01:29 PM	#5
messed up c-10 RHCP afficianado Join Date: Oct 2002 Location: McLoud, OK Posts: 789	Did C-10s and K-10s have the same rear axle? If so I might have some low gears. http://www.chuckschevytruckpages.com/73-87specs.html Down at the bottom it lists Axle Ratios for K10s. __________________ ~Ryan~ 89 S-10 Blazer with a 4.3L 96 Ford Crown Vic P71 4.6L V8. This car rocks. Here are some links to some good music. Jack Johnson Donavon Frankenreiter

07-02-2003, 04:45 PM	#6
messed up c-10 RHCP afficianado Join Date: Oct 2002 Location: McLoud, OK Posts: 789	Now I'm confused. The RPO codes I got off of one site doesn't list my rear axle but Mike's site does and it says that I have GQ1: REAR AXLE - STANDARD does that mean I have 2.73's? If I have 2.73's then my truck must have gotten very good mileage with an I-6 and 700-R4. Also for my orginal trans. one site said 700-R4 and Mike's said MX0: MERCHANDISING OPTION ONLY-DO NOT CATALOG Anyone know a good way to see what kind of gears you have without having to take off the differential cover? __________________ ~Ryan~ 89 S-10 Blazer with a 4.3L 96 Ford Crown Vic P71 4.6L V8. This car rocks. Here are some links to some good music. Jack Johnson Donavon Frankenreiter

07-02-2003, 01:16 PM	#3
messed up c-10 RHCP afficianado Join Date: Oct 2002 Location: McLoud, OK Posts: 789	Anyone know what an 84 with a 250 inline six and a four speed would have had in it? __________________ ~Ryan~ 89 S-10 Blazer with a 4.3L 96 Ford Crown Vic P71 4.6L V8. This car rocks. Here are some links to some good music. Jack Johnson Donavon Frankenreiter

07-02-2003, 05:55 PM	#7
SCOTI Registered User Join Date: Apr 2001 Location: DALLAS,TX Posts: 22,064	The earlier 67-72's w/6cyl usually needed a little more gear to get them going (as do most smaller displacement vehicles). Both of the 6cyl's I own came w/3.73's. Of course things changed in 73, but I would still guess 6cyl's came w/@ least 3.42's. __________________ 67SWB-B.B.RetroRod 64SWB-Recycle 89CCDually-Driver/Tow Truck 99CCSWB Driver All Fleetsides @rattlecankustoms in IG Building a small, high rpm engine with the perfect bore, stroke and rod ratio is very impressive. It's like a highly skilled Morrocan sword fighter with a Damascus Steel Scimitar..... *Cubic inches is like Indiana Jones with a cheap pistol.*

07-02-2003, 07:08 PM	#8
Prerunner1982 Registered User Join Date: Oct 2002 Location: Edmond, OK Posts: 5,904	gq1 i believe is the 3.07s or 3.08s atleast thats what mine says i have. __________________ Jon 1982 Chevy Silverado 350/th350.... RETIRED 1993 Jeep XJ 2 door(Cherokee) 4wd 4.0ltr/AX-15 (5spd)/NP231 .... Oklahoma Roll Call

07-02-2003, 09:10 PM	#9
83C Registered User Join Date: May 2003 Location: Il Posts: 90	My truck came from factory with a I-6 and a 4-speed with the GQ1 rearend. I took the differential cover off and counted the teeth and it have 2.73 gears. __________________ 83 Chevy SWB http://www.cardomain.com/id/letheridge

07-02-2003, 09:23 PM	#10
Prerunner1982 Registered User Join Date: Oct 2002 Location: Edmond, OK Posts: 5,904	ok i am stupid. hence the user text! __________________ Jon 1982 Chevy Silverado 350/th350.... RETIRED 1993 Jeep XJ 2 door(Cherokee) 4wd 4.0ltr/AX-15 (5spd)/NP231 .... Oklahoma Roll Call

07-02-2003, 09:31 PM	#11
SCOTI Registered User Join Date: Apr 2001 Location: DALLAS,TX Posts: 22,064	Prerunner, I have some buddies here in DFW that are in a band called . . .... The VillageIdiots. Check out their site @ IdiotsVillage.com __________________ 67SWB-B.B.RetroRod 64SWB-Recycle 89CCDually-Driver/Tow Truck 99CCSWB Driver All Fleetsides @rattlecankustoms in IG Building a small, high rpm engine with the perfect bore, stroke and rod ratio is very impressive. It's like a highly skilled Morrocan sword fighter with a Damascus Steel Scimitar..... *Cubic inches is like Indiana Jones with a cheap pistol.*

07-02-2003, 10:16 PM	#12
swervin ervin You get what you pay for Join Date: Dec 1999 Location: Cherryville, NC Posts: 4,798	GQ1 just means it's a non posi rear. G80 is for posi. Standard means what was standard for the year. It gets confusing sometimes. Look on the front of the passenger side axle tube about 3 - 5 inches from the carrier. See if there is an RPO code stamped there. I'm pretty sure if there is a code, the first three letters will tell you what gear it came stock with. Let me know if you find a code and what the first three letters are. I also need to know what rear brakes you have. 11 x 2, or 11 x 2.75. __________________ Mike 1985 Chevy C-10

07-02-2003, 10:16 PM	#13
gldevall Registered User Join Date: Mar 2003 Location: Walker, LA Posts: 2,925	GU2 is 2.73 __________________ Gary -1986 SWB: lowered 4/6, SOLD!!! -Best 1/4 mile: 14.51 @ 91.01 MPH -2001 Pewter Tahoe, billet grill, Corsa Sport Cat-back, K&N FIPK SOLD!!! -2004 Z-71 Extended cab with a flowmaster, BDS 6.5", 3" BL, 35x12.5x18 Trail Grapplers on Pro-Comp 18x9 wheels

07-02-2003, 10:21 PM	#14
gldevall Registered User Join Date: Mar 2003 Location: Walker, LA Posts: 2,925	Found it. RPO CODES (CHEVY). ... RATIO GM3 : AXLE REAR, 3.45 RATIO GM8 : AXLE REAR,... 2.56 RATIO GQ1 : AXLE, STD ... ENGINE, GAS, 6 CYL, 2.8L, 2BBL, V6, 60 DEG, TRUCK LR6 : ENGINE __________________ Gary -1986 SWB: lowered 4/6, SOLD!!! -Best 1/4 mile: 14.51 @ 91.01 MPH -2001 Pewter Tahoe, billet grill, Corsa Sport Cat-back, K&N FIPK SOLD!!! -2004 Z-71 Extended cab with a flowmaster, BDS 6.5", 3" BL, 35x12.5x18 Trail Grapplers on Pro-Comp 18x9 wheels

07-02-2003, 10:43 PM	#15
swervin ervin You get what you pay for Join Date: Dec 1999 Location: Cherryville, NC Posts: 4,798	Uhh, I don't know where you got this from, but our trucks never came with a 2.8 V6, and especially a 60 deg one. My 85 was a GQ1, and it came with 2.73's, which are RPO code GU2. GQ1 only means non posi. Look at this sheet that was in the dash of my truck when I bought it. http://www.73-87.com/photos/old/build_sheet.jpg



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07-02-2003, 10:56 PM	#16
ElGracho Gentleman Jim Driver Join Date: Nov 2002 Location: Poulsbo, WA Posts: 1,553	I figured KIILew would have been in on this one by now, but GQ1 doesn't mean non posi or any specific axle ratio. It means "Standard Axle Ratio" which you can look up in a table for your GVW, your engine, your trans, and your body style (Long bed, short bed, blazer, etc.) For this case, from my 84 Light Duty Chevy Trucks Preliminary Data Book, from the power teams chart on page 78: A 1984 C-10 with a 4900-5600 # GVW, the LE3 4.1l 6 cyl and the MM4 4-sp would have 2.73 gears as its GQ1 option. With the MM7 4-sp, it would have 3.08's. With a 6100# GVW and the MM4 it would have 3.08, and MM7 it would have 3.42. In this case, MM7 is the 4 speed with overdrive and the MM4 is the 4 speed without. Mind you all of these are C10's even with 4 different GVW's. The C20, K10, K20 etc. are all in different tables. On the other hand, the optional axle ratios are fairly easy to decode. GU2 = 2.73, GU4 = 3.08, GU6 = 3.42, GT4 = 3.73, GT5 = 4.10, HC4 = 4.56. As long as you don't have the 'standard' ratio for your particular combo, you can pretty easily figure out what your truck had originally. If you do have the standard ratio, you need a little more information and a table corresponding to your year to figure it out. __________________ Joe '75 GMC Gentleman Jim '84 Chev C10 Short Wide - Super duper plain (manual steering, manual brakes, no dome light, no cig lighter) '85 Chev C10 Short Wide - Super plain Vortec 4.8 4L60E trans also: '81 K30, '83 C30 Crew Dually, '84 M1028 CUCV, '85 M1009 CUCV, another '85 C10 SWB, '89 R3500 Flatbed Last edited by ElGracho; 07-02-2003 at 11:00 PM.

07-02-2003, 11:36 PM	#17
swervin ervin You get what you pay for Join Date: Dec 1999 Location: Cherryville, NC Posts: 4,798	Thanks for clearing the GQ1 thing up. I stand corrected. __________________ Mike 1985 Chevy C-10

07-03-2003, 12:35 AM	#18
messed up c-10 RHCP afficianado Join Date: Oct 2002 Location: McLoud, OK Posts: 789	ok guys heres my RPO sheet. Attached Images __________________ ~Ryan~ 89 S-10 Blazer with a 4.3L 96 Ford Crown Vic P71 4.6L V8. This car rocks. Here are some links to some good music. Jack Johnson Donavon Frankenreiter

07-03-2003, 01:11 AM	#19
TIMSPEED Join Date: Jan 2003 Location: Modesto, CA Posts: 1,321	Hmm..how would I figure out what mine came with? I THINK they're 4.10's (from RPM). But how can I be sure? I didn't see ANY markings on the passenger side axle tube. I DID see some #'s on the actual carrier. Like, #389xxx.. __________________ I have a few cars... See Them Here

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