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9 bolt ???


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#1 cart69

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Posted 29 December 2003 - 10:07 PM

you have all probably heard this before but i saw the topic about the 7.5 rearend and figured i would ask the same of the 9 bolt in my 88 formula, i have a tpi 305 and 700 now and am going to an lt1 6spd will it crap out with the power gain and stick? also is there any place to get a gear for this thing?
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#2 formula13x

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Posted 29 December 2003 - 10:47 PM

The rear-end is the same for the 3rd gen's and the 4th gens that are already powered by that drivetrain, the diff may be different, but they seem to hold up. My rear is a 7.5in 10-bolt, just like yours, and I have the LT1 6-speed combo.
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#3 Exhumed454

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Posted 29 December 2003 - 11:54 PM

is there such thing as a 9 bolt ?....some guy keeps saying he has a 9 bolt...i have a ten bolt ph34r.gif

#4 T-Top T/A

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Posted 30 December 2003 - 06:45 AM

The 9 bolts are the Austrailian rears. There suppose to be alot stronger then the 10s

#5 fireduck350

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Posted 30 December 2003 - 05:31 PM

T-Top T/A is correct about the 9 bolt being an Australian rear end, and it found its way into a lot of 3rd gen F-bodys. They were supposed to be strong, but the problem was and is finding replacement parts for them. If you go to http://www.9bolt.com/
there is a lot of information on there about the 9 bolt and parts for the 9 bolt, including gears.
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#6 87 formula

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Posted 31 December 2003 - 07:47 AM

I am running a borg warner 9 bolt in my camaro behind my stroker and i love it just keep in mind that there is a issue with the brakes and there was a recall for it so if you get one make sure the brakes work on it first
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#7 quickchicken

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Posted 31 December 2003 - 08:55 AM

hers all the details on the 9 bolt. it was a 3 yr run on formulas and GTAs. 87-89.
it was an option on T/As. its rumord to be as strong as or stronger than a dana 44. it IS the strongest rear GM put in an F car ever. as long as you change the fluid and use the GM additive they will last a long time.
the borg is a 7 3/4 rear instead of a 7.5 or 7.625.
the 10 bolt and the 10 bolt are very diff in every way. you cannot yse 10 bolt stuff in a 9 bolt rear.
there is a difference in brakes on thes rears. they went to te PBR brakes in 89 which are half of the 1LE system.
yes the 9 bolt is aussie , thisis why they discontinued these rears as it was more expensive to import so after 89 they dropped the rear and went back to 10 bolts but kept the PBR rear brakes which are found on the 93-97 cars as well
these rears can also be found on camaro models as well, this want a bird only option.
miles has changed the site address, it is now diffsolutions.com . the site is under construction but you can still contact him and he will answer your ques. hes a lil slow but will reply.
miles bought the rights to the brg so he could produce and sell the brg stuff inhte us. he is runningone behind his very modified 427 third gen camaro. that outta tell ya how strong the rear is!!!
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#8 T-Top T/A

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Posted 31 December 2003 - 06:29 PM

QUOTE(quickchicken @ Dec 31 2003, 07:50 AM)
it was a 3 yr run on formulas and GTAs. 87-89.
it was an option on T/As.

I have one out of an 85' Trans Am. I thought that was the first year they were introduced?

I have it for sale in the parts section

#9 quickchicken

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Posted 31 December 2003 - 08:33 PM

QUOTE(T-Top T/A @ Dec 31 2003, 11:24 PM)
QUOTE(quickchicken @ Dec 31 2003, 07:50 AM)
it was a 3 yr run on formulas and GTAs. 87-89.
it was an option on T/As.

I have one out of an 85' Trans Am. I thought that was the first year they were introduced?

I have it for sale in the parts section

T-top im not gonna dispute that as on miles site he has an ol hot rod article with an 85 camaro having the borg rear. but the majority of the borg rears were in 87-89 cars.
ill drop miles an E mail and see what the scoop is on its avail in 85. also Randys ring and pinion has gears but they arent borg they are yukon. i havent researched into that yet.
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run it wide open till ya see god "THEN" brake !!

#10 T-Top T/A

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Posted 01 January 2004 - 12:15 AM

Yeah, I was surprised when I pulled the rear and saw the Borg-warner stamp on it. It is a 9 bolt (non posi) Drum rear . I bought the car from the original owner, (my neighbor) and Its all Original.

The car has the LG4 engine, so Its pretty basic when It comes to performance.

Would anyone know what Gear Ratio came in these in 85? I dont want to pull the cover. Everything I read said 3.27s

#11 quickchicken

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Posted 01 January 2004 - 01:01 AM

you have 3 ratios that could poss be in that rear. a 2.77 ,3.08 or the 3.27. during the time the previous owner had the car the tag that is attached by the bolts must have goten pitched.
if the RPOs are on te console it will be listed there.
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run it wide open till ya see god "THEN" brake !!

#12 T-Top T/A

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Posted 01 January 2004 - 02:32 AM

Aaahhh, It does have the metal tag and It says 3.08 . I took a peice of scotch bright and cleaned it, I didnt know It had the ratio on there.

Thanks , quickchicken smile.gif

#13 Mongoose

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Posted 01 January 2004 - 04:21 PM

The gear ratio will be stamped into the ring gear itself if you want to take the cover off and look to make sure. If your planning to use a 6 speed then you may want to stick with ratios of 3.45 and up. A 3.70 ratio and I believe a 4.10 was offered at one time for the 9 bolt.
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#14 T-Top T/A

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Posted 01 January 2004 - 07:41 PM

Its for sale. I already swapped in another 9 bolt (posi disk ) from a 89 formula.

#15 quickchicken

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Posted 02 January 2004 - 02:50 AM

QUOTE(Mongoose @ Jan 1 2004, 09:16 PM)
The gear ratio will be stamped into the ring gear itself if you want to take the cover off and look to make sure. If your planning to use a 6 speed then you may want to stick with ratios of 3.45 and up. A 3.70 ratio and I believe a 4.10 was offered at one time for the 9 bolt.

DOH1 i forgot about it being stamped into the gear! rochmond and DTS sells a 3.70 gear. Miles makes and sells upper ratio gears past 3.70-3.73 if they are needed.
83 T/A 350 T-5
89 FORMULA T-5 LB9
run it wide open till ya see god "THEN" brake !!




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