5 Speed Rumors...

SnoMan · 10-31-2009, 03:51 PM

I have heard 3 things multiple time that involve 5 speed s10s, blazers. one being that they all had a cast iron fron dif. two beinf the rear axle is the "same" as a zr2 and 3 that the gearing is always 3.43. Is there anyone tht has the glove box codes so i can look it up or can just tell me which rumors are true and which ones arent? yes i did search ad got nuthin so dont flame.

Drumer919 · 10-31-2009, 04:03 PM

Off the top of my head GU6 is for 3:42's, dont know the others though.

hom3gr0wn · 10-31-2009, 09:09 PM

theres a post on the 2.2 2nd gen forums for the rear axle codes not sure if they work for the 4x4 or not...

***philntx*** · 10-31-2009, 10:29 PM

RPO codes for rear axle ratios are the same across all S/T models

There isn't a separate RPO code for aluminum/iron front differential. However, I have only seen an Iron case front differential under a 5 speed Gen 2 Blazer, not an automatic Blazer.

SnoMan · 11-01-2009, 08:53 AM

Quote: Originally Posted by philntx

RPO codes for rear axle ratios are the same across all S/T models

There isn't a separate RPO code for aluminum/iron front differential. However, I have only seen an Iron case front differential under a 5 speed Gen 2 Blazer, not an automatic Blazer.

I looked at mine and the rear end has 3.42 gearing with the posi in it. As for the front i was looking at it and it looks like cast iron but m not 100% (and yes it is a 2nd gen blazer 5 speed)

cpolaris502 · 11-01-2009, 12:50 PM

My 2dr 2wd 5sp has an 8.5" rear end with 3.42s

95 S_Trucker · 11-01-2009, 01:03 PM

thats a myth that all 5-speed 4wds had the cast iron front diff, my 95 was aluminum

SnoMan · 11-02-2009, 07:52 AM

S not all had them but it is possible right? and is there a code/design feature that would help me identify it?

95 S_Trucker · 11-02-2009, 08:36 AM

crawl underneath with a magnet and see if it sticks

S10dude · 11-02-2009, 09:02 AM

great idea !

SnoMan · 11-02-2009, 03:43 PM

I will be 10% honest and say i never thought of that

Are there any codes to verify the rear end size or no?

**Kampz69** · 11-02-2009, 05:56 PM

GU6 is a 3.42, G80 is govloc. i dont believe there is an RPO for the 8.5 rear, youd just have to look at it. and yes try the magnet method on the front, but i thought that the iron front diffs were black in color.

SnoMan · 11-02-2009, 06:39 PM

Black as in color/paint/powdercoat? And i noticed that the dome overide thing (press it a certain amount of times and the running lights go out) doesnt work but it didnt work on my friends 98 5 speed pick up when he had it. Is this common thru all the 5 speeds?

**Kampz69** · 11-02-2009, 06:50 PM

black as in paint i think, otherwise they would all be rusty within a few miles. ive never seen an iron one in person as mine is aluminum so i really cant say for sure. the dome override trick didnt work in my 99 but it did in my 2000, so i dont know what to tell you there lol

GeorgesBlazah · 11-03-2009, 11:15 PM

The dome override works on 2000+. Also im pretty sure youll find Iron Cases on the awd Bravadas and most fo the time they should be on the Autotrac trucks as well.

beedle4 · 11-03-2009, 11:23 PM

I have only seen iron diff on 5-speeds.

I bought a junk bravada diff for the shaft and it was aluminum, as with most autotracs too.

And the 8.5 axle was on some non Z's too.

b1lk1 · 11-03-2009, 11:43 PM

Auto-trac here and my front diff is definitely aluminum.

**Kampz69** · 11-04-2009, 02:03 PM

yea mine 99 is an autotrac and its aluminum, i think my 00 NP1 is aluminum too. both autos obviously.

i thought all ZR2's had 8.5 rears? was it only certain years and up?

Drumer919 · 11-04-2009, 03:40 PM

If someone with a 8.5 rear can get me all their codes I will find out what one is 8.5, its hard looking threw all of them though, my list has every RPO code ever used on any vehicle, so its extremely long.

I can do the same thing for someone with a iron front diff, the only thing I found interesting so far, other than front axle GVW and ratios, is FE8-FRT DIFF CARR DR AXLE.

beedle4 · 11-04-2009, 03:59 PM

Yes all ZR2's had the 8.5/8.6 rear end.

But some non Z got it too.

Cylheadman · 11-07-2009, 09:09 PM

1998 blazer 5 speed 3.42, cast iron dif

SnoMan · 11-08-2009, 07:23 PM

So today i had my truck out and i did the magnet test and it stuck so it looks like i got the iron front diff lol and ik for a fact i got the 8.5 rear so looks like is got a pretty good setup from the factory

FoolThrottle · 11-08-2009, 08:57 PM

2000 Blazer LS 4x4 2dr. 5-spd

-Cast iron front diff. 3.42s
-8.5 rear diff 3.42s and G80.
-press the dome override X4 and the lights go out, press X4 again and they go back on.

Just wanted to add my 2 cents

10-31-2009, 03:51 PM	#1
SnoMan Registered User Join Date: Apr 2009 Posts: 120 Location: Hilton NY User is: OffLine	5 Speed Rumors... I have heard 3 things multiple time that involve 5 speed s10s, blazers. one being that they all had a cast iron fron dif. two beinf the rear axle is the "same" as a zr2 and 3 that the gearing is always 3.43. Is there anyone tht has the glove box codes so i can look it up or can just tell me which rumors are true and which ones arent? yes i did search ad got nuthin so dont flame.
	[Reply w/Quote]

10-31-2009, 04:03 PM	#2
Drumer919 Registered User Age: 22 Join Date: Dec 2005 Posts: 67 Location: Grove City, Ohio User is: OffLine	Re: 5 Speed Rumors... Off the top of my head GU6 is for 3:42's, dont know the others though.
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10-31-2009, 09:09 PM	#3
hom3gr0wn Registered User Join Date: Sep 2006 Posts: 25 Location: User is: OffLine	Re: 5 Speed Rumors... theres a post on the 2.2 2nd gen forums for the rear axle codes not sure if they work for the 4x4 or not...
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10-31-2009, 10:29 PM	#4
*philntx* Build them right....Mod Age: 54 Join Date: Jul 2006 Posts: 2,123 Location: Plano TX User is: OffLine	Re: 5 Speed Rumors... RPO codes for rear axle ratios are the same across all S/T models There isn't a separate RPO code for aluminum/iron front differential. However, I have only seen an Iron case front differential under a 5 speed Gen 2 Blazer, not an automatic Blazer. Last edited by philntx : 10-31-2009 at 10:39 PM.
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11-01-2009, 08:53 AM	#5
SnoMan Registered User Join Date: Apr 2009 Posts: 120 Location: Hilton NY User is: OffLine	Re: 5 Speed Rumors... Quote: Originally Posted by philntx RPO codes for rear axle ratios are the same across all S/T models There isn't a separate RPO code for aluminum/iron front differential. However, I have only seen an Iron case front differential under a 5 speed Gen 2 Blazer, not an automatic Blazer. I looked at mine and the rear end has 3.42 gearing with the posi in it. As for the front i was looking at it and it looks like cast iron but m not 100% (and yes it is a 2nd gen blazer 5 speed)
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11-01-2009, 12:50 PM	#6
cpolaris502 The Dreamsicle Age: 20 Join Date: Jul 2005 Posts: 16,049 Location: Rogers, MN User is: OffLine	Re: 5 Speed Rumors... My 2dr 2wd 5sp has an 8.5" rear end with 3.42s
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11-01-2009, 01:03 PM	#7
95 S_Trucker no longer has a 95 Age: 20 Join Date: Jan 2007 Posts: 1,715 Location: Lancaster, PA User is: OffLine	Re: 5 Speed Rumors... thats a myth that all 5-speed 4wds had the cast iron front diff, my 95 was aluminum
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11-02-2009, 07:52 AM	#8
SnoMan Registered User Join Date: Apr 2009 Posts: 120 Location: Hilton NY User is: OffLine	Re: 5 Speed Rumors... S not all had them but it is possible right? and is there a code/design feature that would help me identify it?
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11-02-2009, 08:36 AM	#9
95 S_Trucker no longer has a 95 Age: 20 Join Date: Jan 2007 Posts: 1,715 Location: Lancaster, PA User is: OffLine	Re: 5 Speed Rumors... crawl underneath with a magnet and see if it sticks
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11-02-2009, 09:02 AM	#10
S10dude workin it ! Join Date: May 2006 Posts: 11,022 Location: Sacramento,Ca. User is: OffLine	Re: 5 Speed Rumors... great idea !
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11-02-2009, 03:43 PM	#11
SnoMan Registered User Join Date: Apr 2009 Posts: 120 Location: Hilton NY User is: OffLine	Re: 5 Speed Rumors... I will be 10% honest and say i never thought of that Are there any codes to verify the rear end size or no?
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11-02-2009, 05:56 PM	#12
Kampz69 Need LSx swap..... Age: 31 Join Date: Feb 2002 Posts: 2,060 Location: SW Chicago burbs User is: OffLine	Re: 5 Speed Rumors... GU6 is a 3.42, G80 is govloc. i dont believe there is an RPO for the 8.5 rear, youd just have to look at it. and yes try the magnet method on the front, but i thought that the iron front diffs were black in color.
	[Reply w/Quote]

11-02-2009, 06:39 PM	#13
SnoMan Registered User Join Date: Apr 2009 Posts: 120 Location: Hilton NY User is: OffLine	Re: 5 Speed Rumors... Black as in color/paint/powdercoat? And i noticed that the dome overide thing (press it a certain amount of times and the running lights go out) doesnt work but it didnt work on my friends 98 5 speed pick up when he had it. Is this common thru all the 5 speeds?
	[Reply w/Quote]

11-02-2009, 06:50 PM	#14
Kampz69 Need LSx swap..... Age: 31 Join Date: Feb 2002 Posts: 2,060 Location: SW Chicago burbs User is: OffLine	Re: 5 Speed Rumors... black as in paint i think, otherwise they would all be rusty within a few miles. ive never seen an iron one in person as mine is aluminum so i really cant say for sure. the dome override trick didnt work in my 99 but it did in my 2000, so i dont know what to tell you there lol
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11-03-2009, 11:15 PM	#15
GeorgesBlazah Slap my meat on your pita Age: 24 Join Date: Sep 2004 Posts: 7,214 Location: south jersey User is: OffLine	Re: 5 Speed Rumors... The dome override works on 2000+. Also im pretty sure youll find Iron Cases on the awd Bravadas and most fo the time they should be on the Autotrac trucks as well. Last edited by GeorgesBlazah : 11-03-2009 at 11:17 PM.
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11-03-2009, 11:23 PM	#16
beedle4 Registered User Age: 22 Join Date: May 2007 Posts: 1,152 Location: User is: OffLine	Re: 5 Speed Rumors... I have only seen iron diff on 5-speeds. I bought a junk bravada diff for the shaft and it was aluminum, as with most autotracs too. And the 8.5 axle was on some non Z's too.
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11-03-2009, 11:43 PM	#17
b1lk1 Dain Bramaged Age: 41 Join Date: Jun 2009 Posts: 47 Location: Ontario, Canada User is: OffLine	Re: 5 Speed Rumors... Auto-trac here and my front diff is definitely aluminum.
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11-04-2009, 02:03 PM	#18
Kampz69 Need LSx swap..... Age: 31 Join Date: Feb 2002 Posts: 2,060 Location: SW Chicago burbs User is: OffLine	Re: 5 Speed Rumors... yea mine 99 is an autotrac and its aluminum, i think my 00 NP1 is aluminum too. both autos obviously. i thought all ZR2's had 8.5 rears? was it only certain years and up?
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11-04-2009, 03:40 PM	#19
Drumer919 Registered User Age: 22 Join Date: Dec 2005 Posts: 67 Location: Grove City, Ohio User is: OffLine	Re: 5 Speed Rumors... If someone with a 8.5 rear can get me all their codes I will find out what one is 8.5, its hard looking threw all of them though, my list has every RPO code ever used on any vehicle, so its extremely long. I can do the same thing for someone with a iron front diff, the only thing I found interesting so far, other than front axle GVW and ratios, is FE8-FRT DIFF CARR DR AXLE. Last edited by Drumer919 : 11-04-2009 at 03:44 PM.
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11-04-2009, 03:59 PM	#20
beedle4 Registered User Age: 22 Join Date: May 2007 Posts: 1,152 Location: User is: OffLine	Re: 5 Speed Rumors... Yes all ZR2's had the 8.5/8.6 rear end. But some non Z got it too.
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11-07-2009, 09:09 PM	#21
Cylheadman Registered User Age: 26 Join Date: Oct 2008 Posts: 3 Location: User is: OffLine	Re: 5 Speed Rumors... 1998 blazer 5 speed 3.42, cast iron dif
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11-08-2009, 07:23 PM	#22
SnoMan Registered User Join Date: Apr 2009 Posts: 120 Location: Hilton NY User is: OffLine	Re: 5 Speed Rumors... So today i had my truck out and i did the magnet test and it stuck so it looks like i got the iron front diff lol and ik for a fact i got the 8.5 rear so looks like is got a pretty good setup from the factory
	[Reply w/Quote]

11-08-2009, 08:57 PM	#23
FoolThrottle Registered loser Age: 31 Join Date: Jul 2007 Posts: 154 Location: PA User is: OffLine	Re: 5 Speed Rumors... 2000 Blazer LS 4x4 2dr. 5-spd -Cast iron front diff. 3.42s -8.5 rear diff 3.42s and G80. -press the dome override X4 and the lights go out, press X4 again and they go back on. Just wanted to add my 2 cents
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