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Need advice

Kyle1983

Kyle1983

1/2 ton status
Joined
Sep 22, 2019
Posts
172
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Location
Sweden
I have a 88 Blazer 4x4 with a 383. 700R4 tranny. Lifted with 35' tires. 2.73 geared gov lock rear end. It's in really good condition.

Ran the vehicle service parts sticker.
Said I have a 2.73 geared gov lock rear axle.

I heard that the gov-lock is a time bomb. Especially with tires that are over sized and a heavy right foot.

I live in Sweden and so locating used replacement parts will never happen. I have to purchased and import. What rear axle is affordable yet bulletproof and worth me investing my money to import?

I don't use 4WD and go "mudding" It is more of just a summer cruising vehicle. received_354839615458085.jpeg received_705558126558533.jpeg received_369318670667811.jpeg received_1714165358727472.jpeg received_420216442034053.jpeg received_666128800559668.jpeg received_630147797391029.jpeg
 
Kyle1983 said:
I have a 88 Blazer 4x4 with a 383. 700R4 tranny. Lifted with 35' tires. 2.73 geared gov lock rear end. It's in really good condition.

Ran the vehicle service parts sticker.
Said I have a 2.73 geared gov lock rear axle.

I heard that the gov-lock is a time bomb. Especially with tires that are over sized and a heavy right foot.

I live in Sweden and so locating used replacement parts will never happen. I have to purchased and import. What rear axle is affordable yet bulletproof and worth me investing my money to import?

I don't use 4WD and go "mudding" It is more of just a summer cruising vehicle. View attachment 315771 View attachment 315772 View attachment 315773 View attachment 315774 View attachment 315775 View attachment 315776 View attachment 315777
Click to expand...
I say you're axle should be fine but the gearing could kill your transmission so I would get some 4.10 gears and while you're at it if you want to change from the gov loc get limited slip carrier it will work for what you want.
 
Thanks for the reply! So keep the axle just switch out the "internals"? 4.10 gears and get a limited slip carrier. I am not so mechanically inclined. Any help with a purchase list, websites would really help. The vehicle has had many owners, I suppose I should remove the cover first and verify it still has those gears.

Why will those gears kill the tranny? Just curious?
 
The truck has to work a lot harder to get up to speed with the 2.73s . (Might actually be 3.73s) I would pull the cover and check the gears. Ratio should be stamped on the ring. 4.10 gears will be easier on the drivetrain/more acceleration


determine-gear-ratio-ring-gear.png
 
Or you can jack up rear axle and count rotations of pinion (so you dont have to drain diff) for a single rotation of tire with truck in neutral.

Your axle should be fine, you would likely want to source 4.10 gear sets (can find fairly easy in US and have shipped to you).
 
muddybuddy said:
Or you can jack up rear axle and count rotations of pinion (so you dont have to drain diff) for a single rotation of tire with truck in neutral.

Your axle should be fine, you would likely want to source 4.10 gear sets (can find fairly easy in US and have shipped to you).
Click to expand...
That works too
 
I'm thinking you have 3.73 vs 2.73's. I don't think it was offered in 88'. My 89' had 3.42's and that was the highest available at that time (I believe).

If it is 3.73's, I don't know if 4.10's will be worth the dollars to swap. I'd go 4.56's if you were going to spend the money.

My glovebox RPO is GU6 - 3.42's
 
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bsgreen said:
The truck has to work a lot harder to get up to speed with the 2.73s . (Might actually be 3.73s) I would pull the cover and check the gears. Ratio should be stamped on the ring. 4.10 gears will be easier on the drivetrain/more acceleration


View attachment 315781
Click to expand...

Thank you for the reply! Do I have to use some sealant when putting the cover back on?
 
Last edited:
muddybuddy said:
Or you can jack up rear axle and count rotations of pinion (so you dont have to drain diff) for a single rotation of tire with truck in neutral.

Your axle should be fine, you would likely want to source 4.10 gear sets (can find fairly easy in US and have shipped to you).
Click to expand...

Thank you for this information. I will try this method. I have a jack and stands. Shouldn't be too difficult.
 
jeff in co said:
I'm thinking you have 3.73 vs 2.73's. I don't think it was offered in 88'. My 89' had 3.42's and that was the highest available at that time (I believe).

If it is 3.73's, I don't know if 4.10's will be worth the dollars to swap. I'd go 4.56's if you were going to spend the money.

My glovebox RPO is GU6 - 3.42's
Click to expand...

received_739176359871852.jpeg

GU2 G80

2.73 and Gov lock right?

Ok so upgrade the gears but what about that gov lock? I heard it's best to get rid of it?
 
jeff in co said:
Yea, sure looks correct. Looks very similar to mine except the GU2. Dang that's high!
Click to expand...

So is it agreed that 2.73 gearing could possibly put unnecessary strain on the 700R4 tranny? Increasing the possibility of failure?

Let's say I want to remove the gov lock and go with 4.10 gearing. What do I need to buy and what cost am I looking at?
 
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Kyle1983 said:
Thank you for the reply! Do I have to use some sealant when putting the cover back on?
Click to expand...

Yes, you need sealant. Good ol' RTV sealant or something similar will work fine. 2.73s are definitely high gears, but that seems like a pretty nice build so the gears may have been changed already. I'd try one of the above methods to confirm the gear ratio before you worry about it too much..
 
jeff in co said:
Yea, sure looks correct. Looks very similar to mine except the GU2. Dang that's high!
Click to expand...
Yeah I thought it was unlikely when I traded for the 85 k5 I got but I confirmed by opening the cover and sure enough it was 2.73
With nv4500 might not be so bad coupled with a big block, but then you'll have to worry about breaking the gov loc.
 
Ok so 35' tires and 2.73 gears will destroy the tranny. 400 HP from the 383 is also too much for the tranny. The gov lock is a ticking time bomb. So I have to change out from 2.73 to 3.73 and rebuild the tranny? A lot of extra unforeseen BS.
 
Kyle1983 said:
Ok so 35' tires and 2.73 gears will destroy the tranny. 400 HP from the 383 is also too much for the tranny. The gov lock is a ticking time bomb. So I have to change out from 2.73 to 3.73 and rebuild the tranny? A lot of extra unforeseen BS.
Click to expand...


I wouldn't get discouraged about it. I don't think you really need to worry about the 400hp or the gov loc, so much as the gears as long as you aren't slamming the skinny pedal down all the time. If you are just using it to cruise it's not gonna be a big issue. Your biggest problem will be the 2.73 gears if that is what is still in the axles. If you do still have 2.73 gears, probably best to swap to 4.10 or 4.56 gears.

Step 1 will be to confirm what gears you have and go from there.
 
^^^ Agreed. I'd pull the cover and see what you have specifically.

Stamping on Ring:
41:15 is a 2.73 gear set
41:11 is a 3.73 gear set
41:10 is a 4.10 gear set
37:9 is a 4.11 gear set

Correct me if I'm wrong......
 
If you are pulling the cover, make sure it’s even a govlock still. Look for spider gears.

If it’s a cruiser, look for a stock open carrier locally. I know it’s Sweden, but those 10bolt axles are worldwide everywhere. Might find one, saving the expense. You don’t need to spend the money on a new carrier when it has 4x4 for those needed moments. Once the gearing is confirmed, we can discuss 4:10 or 4:56 with those 35s.

My 2 cents :/
 
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