Differential (non-HD 3.05 to 3.29) swap questions... - GM Forum - Buick, Cadillac, Chev, Olds, GMC & Pontiac chat


Performance, Brainstorming & Tuning Talk about modifications, or anything else associated with performance enhancements. Have a new idea for performance/reliability? Post it here. No idea is stupid! (please use Detailing and Appearance for cosmetic ideas)

Reply
 
 
 
Thread Tools Search this Thread
Old 10-27-2007, 03:48 PM   #1
Senior Member
Posts like a Corvette
Thread Starter
 
Join Date: Jan 2007
Location: San Diego, CA
Posts: 1,451
Thanks: 0
Thanked 0 Times in 0 Posts
agrazela is on a distinguished road
Default Differential (non-HD 3.05 to 3.29) swap questions...

So I decided to proceed with bumping up the gearing on the '98 LeSabre from 3.05 to 3.29:
http://www.bonnevilleclub.com/forum/...ic.php?t=87642

(This is IMO a "performance" mod...but feel free to move this thread if in the wrong forum)

Right now I'm in the "research stage," so of course I've got a ton of questions.

Again, AFAIK, all I need is:
-a 3.29 W-body (e.g.) non-HD differential and sun gear and thrust bearings
-a new extension housing seal and right axle oil seal

Is this correct? Any other parts I'd need?

As for parts removal, looking at the FSM, it seems I've got to:
1. drain the transaxle
2. pop the ball joint (using special GM tool if possible, to avoid splitting boot)
3. disengage axle from hub (using puller...Autozone loaner??? )
4. remove the halfaxle from tranny (planning on using the wood block and hammer trick)
5. remove the extension housing
6. remove the differential, sun gear, thrust bearings

I think I'm mostly good up to step 4 (although, what size is the hub nut?)...it'* removing the differential I have some questions about:

It looks like I've got to pop a snap ring (seemingly alternately numbered 509 or 512 in the FSM, depending on which diagram I look at) loose on the output shaft.
The FSM calls for a special tool that looks like a big chisel or flat blade screwdriver...do I really need this special tool?

Once "popped loose", will I need to completely remove this snap ring to slip the current differential, sun gear, thrust bearings, etc. off (and put the replacement parts on)?
If so, what tool do I need for that? Is this a standard snap ring (with holes in the ends)?
Will this snap ring be reuseable? If not, is there a GM part number for the snap ring?

Will I need a special tool(*) for removing and replacing the right axle oil seal in the extension housing?

Anything else I'm overlooking? Other tips / hints?

Thanks

EDIT: I originally thought I might need a different right side axle...I now no longer believe this, since Lumina/Monte Carlo come in 3.05 or 3.29 configurations, and both ratios use the same axle (according to Rock Auto)
agrazela is offline   Reply With Quote
Old 10-28-2007, 04:27 PM   #2
DINOSAURUS BOOSTUS

Expert Gearhead
 
BillBoost37's Avatar
 
Join Date: Mar 2005
Location: Enfield, CT
Posts: 41,391
Thanks: 0
Thanked 0 Times in 0 Posts
BillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of light
Default

Axle nut first.. and before you take the nut totally off.. whack the axle inward with a hammer. This will keep you from needing a special press tool.

As for the special tool to pop the ball joint. If you have a helper and a long (4'+) bar it'* a snap. The car will be jacked up, merely undo the balljoint nut (and cotter pin) then have your helper put a ton of force down on the A arm. If that doesn't pop it free.. whack the lower part of the ball joint with a hammer while pressure is applied. Unbolting the end link can be helpful.

Remove the axle and use a strap or something to hold the strut out of the way. The axle from trans removal can be a pain. Do not pull on the axle as you'll pull the CV joints apart. Use a large screwdriver or prybar to pop it out. The snapring inside will resist if you put constant force on it.

Then you get the housing off the trans. I found that pulling the driverside axle was necessary to get the Diff out far enough to pop it off the shaft. At that point..it'* super easy.

The seal will probably be a pain.. Use your judgement.
BillBoost37 is offline   Reply With Quote
Old 10-28-2007, 04:55 PM   #3
Senior Member
Posts like a Corvette
Thread Starter
 
Join Date: Jan 2007
Location: San Diego, CA
Posts: 1,451
Thanks: 0
Thanked 0 Times in 0 Posts
agrazela is on a distinguished road
Default

Thanks for the tips, Bill.

I bought the balljoint J-tool on EBAY, so I'll be using that. I'll try the hammer whack on the axle hub.

I've got a good prybar, so if the wood block/hammer trick doesn't work, I'll try that.

When you say "the seal is a pain," do you mean installation of a new seal? Can I reasonably expect to be able to re-use the old seal?

Thanks for the heads up on possibly having to remove the driver'* side axle...was that necessary so you could push (or pull) the output shaft toward the passenger'* side?

Also, you didn't address the snap ring at the end of the output shaft...will I just need a big flatblade and a standard snap ring tool for that?
agrazela is offline   Reply With Quote
Old 10-28-2007, 05:16 PM   #4
Senior Member
Posts like a Camaro
 
Join Date: Oct 2006
Location: montreal canada NEBF07 ONBF07
Posts: 987
Thanks: 0
Thanked 0 Times in 0 Posts
firebuick is on a distinguished road
Default

hi nice project are doing any test before and after the change to see what gain youre getting .performmance wise and MPG
firebuick is offline   Reply With Quote
Old 10-28-2007, 05:16 PM   #5
Senior Member
True Car Nut
 
Join Date: Jul 2006
Location: Granville, Ohio ~NEBF '07 Survivor~
Posts: 5,001
Thanks: 0
Thanked 0 Times in 0 Posts
petraman is on a distinguished road
Default

Don't you need to change some PCM tables to be compatible with the taller gear ratio???
petraman is offline   Reply With Quote
Old 10-28-2007, 05:18 PM   #6
Senior Member
Posts like a Camaro
 
Join Date: Oct 2006
Location: montreal canada NEBF07 ONBF07
Posts: 987
Thanks: 0
Thanked 0 Times in 0 Posts
firebuick is on a distinguished road
Default

Quote:
Don't you need to change some PCM tables to be compatible with the taller gear ratio???

for him i think that the easy part of the swap whit his tuner
firebuick is offline   Reply With Quote
Old 10-28-2007, 05:28 PM   #7
Senior Member
True Car Nut
 
Join Date: Jul 2006
Location: Granville, Ohio ~NEBF '07 Survivor~
Posts: 5,001
Thanks: 0
Thanked 0 Times in 0 Posts
petraman is on a distinguished road
Default

Whoops, didn't know he had one...
petraman is offline   Reply With Quote
Old 10-28-2007, 06:50 PM   #8
Senior Member
Posts like a Corvette
Thread Starter
 
Join Date: Jan 2007
Location: San Diego, CA
Posts: 1,451
Thanks: 0
Thanked 0 Times in 0 Posts
agrazela is on a distinguished road
Default

Tuning the PCM is the easy part

As to before / after, I guess we'll see how it affects 0-60 time; also, I have tracked mpg, and I currently get a consistent 19-20 mpg in my normal everyday commuting, and anywhere from 30-35 mpg on typical family vacation-type freeway trips depending on traffic (more like 24-25 if towing the popup and with the roof-top cargo carrier).

I bought the differential, so I'd still like some info about tools needed to remove the snap ring on the output shaft...I guess that anyone who has swapped a diffy might be able to help me out on that.

If all goes as planned, this mod will happen over Thanksgiving break.
agrazela is offline   Reply With Quote
Old 10-28-2007, 09:37 PM   #9
Senior Member
True Car Nut
 
95naSTA's Avatar
 
Join Date: Feb 2003
Location: Philly
Posts: 4,508
Thanks: 0
Thanked 0 Times in 0 Posts
95naSTA is on a distinguished road
Default

You can get that snap ring on the output shaft off with two thicker screw drivers. Just run the two screw drivers in the snap ring groove agianst the ends of the snap ring to pop it off. You might want to put a magnet right there to catch it though cause it will fly off.
There are no holes for snap ring pliers.
95naSTA is offline   Reply With Quote
Old 11-05-2007, 06:20 PM   #10
Senior Member
Posts like a Corvette
Thread Starter
 
Join Date: Jan 2007
Location: San Diego, CA
Posts: 1,451
Thanks: 0
Thanked 0 Times in 0 Posts
agrazela is on a distinguished road
Default

OK, got all my parts:

-3.29 non-HD differential and sungear (34 tooth fine pitch); $80 shipped off EBAY; looks brand new
(also included all thrust bearings, washers, a snap ring; and a bunch of stuff I shouldn't need, like the 78-tooth fine-pitch ring gear, parking pawl, output shaft, sungear shaft, etc.)
-right side axle oil seal (if needed); $5 shipped off EBAY
-extension housing seal (if needed); $10 from the dealer

And tools:
-J-36226 balljoint tool; $25 shipped off EBAY (I'm paranoid about ripping the boot)
(tool came as part of a lot of other Kent Moore tools I'll probably never need)
-34mm hub socket; $10 shipped off EBAY
-Motive power fluid extractor (Not needed, but I've been dying for one of these anyway ); $65 shipped off EBAY

I'll probably rent a hub tool from Autozone just to try to make things easier.

If all goes as planned, I'll be doing the swap the week of Nov 18th.
agrazela is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
2006 SILVERADO DIFFERENTIAL QUESTIONS 06silverado Chevrolet 4 04-10-2015 05:57 AM
can i swap my m90 to a non sc gt block? SPEED ADICTIONS Performance, Brainstorming & Tuning 3 05-05-2008 10:52 PM
Questions,Questions,Questions.......... dbeast420 Lounge 2 05-06-2006 03:49 AM
broken differential housing & differential Ishu, tranny Oakleytw 1992-1999 11 12-15-2004 03:00 PM
Questions questions questions big_boss2010 1992-1999 2 09-06-2003 01:41 PM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 07:38 PM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.