2020-B2-5

Author Topic: Opinions on rear gear swap  (Read 2839 times)

b_hill_86

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Re: Opinions on rear gear swap
« Reply #40 on: August 09, 2020, 05:59:38 PM »
For what it’s worth to anyone thinking of axle swapping, very straight forward. Plenty of room to remove without dropping springs, as stated, and wasn’t even real bad to remove the old and installed the new by myself. Just a little ingenuity with a floor jack and ratchet strap. Got the new axle in Friday morning and have been doing some break-in runs. So far, I’m very pleased with the 3.08!
« Last Edit: August 10, 2020, 12:58:54 PM by b_hill_86 »
-Brian-

1977 Trans Am 400 4 speed

nigel

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Re: Opinions on rear gear swap
« Reply #41 on: August 10, 2020, 12:16:12 PM »
Just going to chime in here for what it's worth, rebuilt my 3.42 posi a while back and rebuilt a couple since I would get some books first I would recommend "Chevy differentials how to rebuild the 10 and 12 bolt " also "high-performance differentials axles and drive lines" excellent information.
They are not difficult to rebuild once you understand the procedure, and yes you are going to need special tools but they are not expensive a press is a real advantage for changing bearings a dial (clock) gauge for mesh backlash, inch pound torque gauge  and big sockets. If your going to have a go a new ring and pinion is the way to go much easier to set up mesh go for a good quality one. I clocked one and it was 4 thou out and it didn't get used,you are going to need shims for pinion and shims for diff bearings I would also go with a crush elimination kit  it's a little more work but worth it. Would I do another yes no problem if I was asked, you need to be methodical and be very clean and don't rush when you've done one and set it up correct you will realise there is no black magic to them if you are a fairly confidant mechanic you should have no problems.
 

EscapeRacing

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Re: Opinions on rear gear swap
« Reply #42 on: November 17, 2020, 09:17:43 PM »
Jumping in here. I am doing a rear end rebuild and swap. I currently have a 2.41 posi behind a TH350 with a stock Olds 403. I found a complete working 3.08 posi from a '72 camaro for $150. Just started cleaning it all up today. Plan is to take it completely down to the tubes clean everything up and install 3.23 gears. Assuming the existing carrier is a 3 series and in decent condition, I will reuse it. If not, I will replace. I am going to be purchasing all parts from Jim M. at JD Race and Restoration, whom has been fantastic to work with. I will update as I get things done. Trying to add pics.



« Last Edit: November 17, 2020, 09:35:37 PM by EscapeRacing »

b_hill_86

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Re: Opinions on rear gear swap
« Reply #43 on: November 17, 2020, 10:37:12 PM »
I mentioned in one of your other threads I bought my whole axle assembly, rebuilt, from Jim and am very happy with it. He was very easy to work with and I’d recommend him to anyone. It was just convenient that he’s only about 2 hours from me.

$150 is a good deal! If the ratio is indeed a 3.08 it should be a 3-series carrier unless someone used a spacer on a 2-series to install the 3.08.
-Brian-

1977 Trans Am 400 4 speed

EscapeRacing

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Re: Opinions on rear gear swap
« Reply #44 on: November 19, 2020, 11:21:29 PM »
Agree om Jim. I am 100% buying all the parts to rebuild this from Jim. If it has a 3 series and its in good shape that will save a few bucks, but otherwise I will get a new carrier from him. Thus far I am super impressed with him and really looking forward to working with him on the install. I'm in CA so it will be a phone or video chat....but then seems like they all are these days!! :)

darrylta

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Re: Opinions on rear gear swap
« Reply #45 on: November 20, 2020, 06:31:12 AM »
After looking at the rebuild cost for new gears and other parts and shop hours to do the work.
I elected to purchase a complete 9" rear from Detroit Speed with a 3.50 to 1 ratio.
It will help out the shop that's building the car and I'll know that it was built right.
The only thing I'll have reinforce and check will be the pinion angle.
Darryl

b_hill_86

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Re: Opinions on rear gear swap
« Reply #46 on: November 20, 2020, 07:35:59 AM »
Good luck with the build Escape.

Darryl, I don’t blame you. Part of the reason I ended up buying a rebuilt assembly is it was actually cheaper than I could find anyone to rebuild my axle locally. Plus then that avoided me having to leave the car anywhere
-Brian-

1977 Trans Am 400 4 speed

EscapeRacing

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Re: Opinions on rear gear swap
« Reply #47 on: November 21, 2020, 07:41:51 PM »
Still cleaning the axle I picked up before I open it up to see the carrier. Can anyone help me figure out what is going on here? Is there supposed to be a "hole" here, should it be welded up, add some kind of fitting? The last pic is the other side - havent cleaned that one up yet. I figure I will go under my car and look at the existing axle tomorrow to compare.








Wallington

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Re: Opinions on rear gear swap
« Reply #48 on: November 21, 2020, 07:55:56 PM »
That's where the cast iron housing is welded to the axle tubes, often they only have half that amount. Big torque motors can break the welds and spin the centre.

EscapeRacing

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Re: Opinions on rear gear swap
« Reply #49 on: November 21, 2020, 08:09:34 PM »
Do i need to fill in that hole or plug it? Will that leak fluid?

Wallington

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Re: Opinions on rear gear swap
« Reply #50 on: November 21, 2020, 10:54:58 PM »
Worst decision of my restore was going from 342's to 373's. But that was with a th350 too though.

To be expected, unless you are building a 1/4 mile screamer or have over drive, and perhaps a small block Chev that makes power at higher rpm and not from low down torque.

Wallington

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Re: Opinions on rear gear swap
« Reply #51 on: November 21, 2020, 11:01:07 PM »
Do i need to fill in that hole or plug it? Will that leak fluid?

No, there's no hole, it's welded up and axle tube under it anyway.

EscapeRacing

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Re: Opinions on rear gear swap
« Reply #52 on: November 22, 2020, 09:37:33 PM »
It took tons of scrubbing but i managed to get the axle mostly cleaned. Unfortunately, it looks like its a 2.56 ration based on the GM8 code. I have not been able to decode the other numbers. I'm hoping somebody swapped to a 3 series carrier (vs. using a spacer) as the seller thought it was a 3.08. Obviously will know for sure when i take out the carrier in the next couple of days.








EscapeRacing

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Re: Opinions on rear gear swap
« Reply #53 on: November 22, 2020, 09:38:56 PM »
Whats the right thing to do with the axle as far as paint goes? Scuff it up as much as possible and just paint over the entire thing?

Nexus

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Re: Opinions on rear gear swap
« Reply #54 on: November 23, 2020, 11:58:37 AM »
Yeah, make sure all the oil dirt is off of it. I would use primer, and I would go as far as using etching primer but not entirely necessary. Etching primer will grab the metal a lot better followed by a regular primer but that's me. Decide on the colour of choice and paint it on keeping your bare fingers off all parts that are getting paint. The oils from your skin may compromise the paint adhesion and come off so glove up son!!. :)  Eastwood has chassis paint designed for the under side that works well and looks good but any paint designed for that spot will work.
Charlie

79 Esprit but like many, it will be a T/A clone
(20 years and counting but still have her)
http://transamcountry.com/community/index.php?topic=79648.0

Re: Opinions on rear gear swap
« Reply #54 on: November 23, 2020, 11:58:37 AM »


2020-B1-8


EscapeRacing

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Re: Opinions on rear gear swap
« Reply #55 on: December 13, 2020, 06:55:52 PM »
Made some more progress on the rear end that I picked up today. Pulled out the pinion and all the bearings and races, including the wheel bearings. Cleaned it all up. Not sure if that line on the inside of the housing is a crack or supposed to be there....






JJ 109

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Re: Opinions on rear gear swap
« Reply #56 on: December 13, 2020, 09:49:02 PM »
Casting line. Nothing to worry about.
JJ
76 pro tour project
Twin Turbo LS1
Detroit

Wallington

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Re: Opinions on rear gear swap
« Reply #57 on: December 13, 2020, 11:16:30 PM »
It's had an internal swap as not a 2-series, is it 3.08 as told?

EscapeRacing

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Re: Opinions on rear gear swap
« Reply #58 on: December 14, 2020, 11:47:20 AM »
Wallington - not totally sure what you are asking, but I bought a axle housing assembly that had a 3 series carrier and 3.08 gearing. I am retaining that carrier, but swapping to 3.23 gears and installing all new bearings, races, brake lines, etc. along the way. Then I will drop my existing 2.41 rear and and replace it with the "new" 3.23 rear end.

MNBob

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Re: Opinions on rear gear swap
« Reply #59 on: December 17, 2020, 11:49:26 AM »
You can almost count the ring and pinion teeth from the photo.  The count on the ring divided by the count on the pinion is the ratio.  Some consider 3.08 as the all around best, but it depends on what you want and and the transmission.
1979 TATA Extreme TKO .64
Hedman elite; Pypes 2.5; Borla XS; MSD 6A; Performer intake; open scoop; Sniper QJ;  110 Amp Alt; 4 core radiator/Mark VIII fan; RobbMc mini starter; subframe connectors; solid body mounts; fiberglass rear springs; poly sway bar and link bushings; 81 master; D52’s; Blazer disks; 225/60 & 235/60 17's TrueContact's; relays for PW, PDL, lights; keyless entry

Wallington

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Re: Opinions on rear gear swap
« Reply #60 on: December 17, 2020, 07:34:45 PM »
Wallington - not totally sure what you are asking, but I bought a axle housing assembly that had a 3 series carrier and 3.08 gearing.

All good. One post you were hoping it had a 3-series in it as seller claimed but axle code was 2-series. The pic showed 3-series but turned out to be your spare centre.
« Last Edit: December 17, 2020, 07:39:01 PM by Wallington »

EscapeRacing

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Re: Opinions on rear gear swap
« Reply #61 on: December 18, 2020, 11:11:17 PM »
So some bad news today. Pulled the bearings off the 3 series carrier and it looks like it was spinning on the race and is not really any good to re-use. Bummer. Small delay. I ordered a Yukon Gear Dura Grip posi carrier that should be here this week and the job will continue. Can't hold me back!




EscapeRacing

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Re: Opinions on rear gear swap
« Reply #62 on: December 25, 2020, 03:44:09 PM »
Update - this simple "re-gear and swap" project has encountered some real scope creep!! Not all that abnormal in my world. In case anyone finds this useful, here are the parts and tools I've gathered thus far to swap to a 3.23 rear gear in my 79 Trans Am. Naturally the tools will come in very handy in the years to come. And the learning experience of doing this myself is totally worth it to me.

PARTS
 - $150 > Used rearend from Craigslist that I was hoping would work but as noted above only the housing will be retained
 - $300 > Yukon Gear YDGGM8.5-3-28-1 Differential with Posi (Amazon)
 - $195 > Yukon Gears 3.23 Ring and Pinion Gear (JD Race and Restoration)
 - $95 > Rear end Master Bearing kit (JD Race and Restoration)
 - $35 > Rear axle bearings (JD Race and Restoration)
 - $39 > Yukon Gear Oil and Additive (Amazon)
 - $30 > 2 new wheel cylinders for rear drum brakes (Inline Tube)
 - $10 > Rear drum brake spring kit (Inline Tube)
 - $10 > Rear rubber Brake Hose (Inline Tube)
 - $21 > Rear Brake lines (Inline Tube)
 - $14 > Brake Drum Backing Plate bolts (Firebird Central)
 - $5 > Wheel Cylinder mounting bolts (Firebird Central)
 - $40 > Dana Spicer U-Bolts (Local store)
 - $15 > Spray Paint (Amazon)
 - $7 > Loctite (Amazon)
 - $20 > Wire brushes and cleaning supplies (local store)
 - $20 > Brake cleaner (local store)


TOOLS ACQUIRED
 - $50 > Used bearing press (local transmission shop)
 - $42 > Bearing pullers kit 5-Ton (Amazon)
 - $28 > 10pc Axle Bushing Bearing Race & Seal Removal/Install Driver Master Tool Set (Amazon)
 - $22 > 1/4-inch Drive Beam Torque Wrench - 0-80 Inch/Pounds and 0-9 Newton/Meter Torque Wrench (Amazon)
 - $50 > Dial Indicator (Magnetic Base & Point Precision Inspection Set) (Amazon)
 - $11 > Digital Micrometer (Harbor Freight)
 - $10 > Deadblow Hammer (Harbor Freight)
 - $10 > Transmission Stop-Off Tool

Nexus

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Re: Opinions on rear gear swap
« Reply #63 on: January 05, 2021, 12:21:46 PM »
$1230.00 for a completely rebuilt, stronger rear end that included education and reusable tools for other jobs seems alright to me!!
Charlie

79 Esprit but like many, it will be a T/A clone
(20 years and counting but still have her)
http://transamcountry.com/community/index.php?topic=79648.0

b_hill_86

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Re: Opinions on rear gear swap
« Reply #64 on: January 05, 2021, 03:05:27 PM »
And for what it’s worth, I purchased a new rear assembly from the same JD Race and Restoration shop EscapeRacing purchased some parts from which included a used drum housing, new carrier, new 3.08 gears, bearings and seals for about the same price. Just food for thought for anyone weighing their options. Yea, I don’t get to keep any tools in the end but I didn’t see myself doing a gear swap in the future anyway.

Sorry for the hijack. Although I don’t think it counts as a hijack since I started this thread originally anyway lol
-Brian-

1977 Trans Am 400 4 speed

EscapeRacing

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Re: Opinions on rear gear swap
« Reply #65 on: January 11, 2021, 11:05:32 PM »
Just a quick update - rear end project was mostly on hold last few weeks, but I expect to be back at it more this weekend. I did drive in the front and back pinion races. Front one....easy. Rear one....not so much. The new diff and ring gear look really cool assembled. Cant wait to start working on the teeth patterns.

Nexus

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Re: Opinions on rear gear swap
« Reply #66 on: January 13, 2021, 11:20:26 AM »
Any progress is still progress. Keep us posted!!
Charlie

79 Esprit but like many, it will be a T/A clone
(20 years and counting but still have her)
http://transamcountry.com/community/index.php?topic=79648.0

EscapeRacing

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Re: Opinions on rear gear swap
« Reply #67 on: January 19, 2021, 10:38:06 PM »
Quick update - the new carrier required larger bearings than the ones in my kit. These aftermarket carriers need 1.781 in ID bearings and the OEM carriers use smaller ID bearings. So, add $37 for Ratech Carrier Bearings #9024 from Summit to the above race.

Hope to press them on tomorrow and then start the process of getting the pinion depth correct and carrier shims in place.

Re: Opinions on rear gear swap
« Reply #67 on: January 19, 2021, 10:38:06 PM »
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