Moparts
Tips on making a rear end narrowing jig?
Posted By: markz528
Tips on making a rear end narrowing jig? - 11/21/14 05:06 AM
Need to narrow a 8 3/4. Have a good ground heavy duty shaft to use.
Looking for tips/feedback on how you all made the bushings for the third member and the housing ends. In particular, looking for the clearances between the shaft and the bushings and the clearance to the housing ends.
Does anyone have any pictures?
In addition, any tips would be appreciated on the sequence and precautions to minimize warping. Need to weld the perches on along with the back brace.
Posted By: fourgearsavoy
Re: Tips on making a rear end narrowing jig? - 11/21/14 05:17 AM
I just used the custom Google search on the top of this page and found everything I ever wanted to know about narrowing an 8 3/4 Mopar rear using a home built jig.
I just typed in "rear end jig"
Gus
Posted By: onig
Re: Tips on making a rear end narrowing jig? - 11/21/14 06:43 AM
On mine, a few thousands of an inch between the shaft and pucks that go in the ends and carrier. If they are to loose one or two revolutions of tape to take up the slack. Have done a few and no problems.
Posted By: Jerry Kathe
Re: Tips on making a rear end narrowing jig? - 11/21/14 01:07 PM
Im a welder/machinist by trade but I still purchased my tooling, however I needed tooling for all brands. For your purpose I understand your approach. IMO; machine the adaptors the same OD as the carrier and axle races and the ID to plus .001 - .0015 of the alignment bar.
Welding....this is where it gets tricky....for the order, weld the back brace first then the pads then the ends.
Mig or Tig dictates alot about the process.
Just take your time and skip around allowing ample cool time is about all I can say...this is where experience cant really be clearly explained.
Posted By: jcc
Re: Tips on making a rear end narrowing jig? - 11/21/14 04:23 PM
Jig at pic #47
Pucks are easy to source these are Mittler?
https://board.moparts.org/ubbthreads/show...part=1&vc=1
Posted By: d7cook
Re: Tips on making a rear end narrowing jig? - 11/21/14 05:03 PM
Like someone else said weld the ends last.
My friend made us a jig. Once you have the bar the donuts are easy. I think he used a Mark Williams catalog to give him all the bearing dimensions on every combination we would weld and he made all donuts we would ever need.
Posted By: John_Kunkel
Re: Tips on making a rear end narrowing jig? - 11/21/14 07:45 PM
I got the bar first and then used the outer bearing races for the dimensions to lathe the donuts for each rear end.
Posted By: RobX4406
Re: Tips on making a rear end narrowing jig? - 11/21/14 07:52 PM
Hard to beat this for cost. He has a bunch of stuff for all types of rears, 8.75, Dana, etc.
http://www.ebay.com/itm/Rearend-Narrowin...=item4ac9986473
Posted By: Jerry Kathe
Re: Tips on making a rear end narrowing jig? - 11/21/14 09:36 PM
Thats the exact source I used. Time one buys the raw material and machines all the features, it doesn't make sence to stand in front of a manual lathe doing all of that. I can make denario quicker doing other things.
Not saying thats true for everyone, but it was for me.
Posted By: d7cook
Re: Tips on making a rear end narrowing jig? - 11/21/14 11:31 PM
Quote:
Hard to beat this for cost. He has a bunch of stuff for all types of rears, 8.75, Dana, etc.
http://www.ebay.com/itm/Rearend-Narrowin...=item4ac9986473
We used a much larger shaft diameter. Not sure how much it matters.
Also I always slide a piece of exhaust pipe over the shaft when welding the ends to keep any splatter off the shaft.
Posted By: BigBlockMopar
Re: Tips on making a rear end narrowing jig? - 11/21/14 11:57 PM
Quote:
Thats the exact source I used. Time one buys the raw material and machines all the features, it doesn't make sence to stand in front of a manual lathe doing all of that. I can make denario quicker doing other things.
Not saying thats true for everyone, but it was for me.
I went the MakeMyOwn-way, but I agree those $100 pucks are the way to go.
Been using this axle for about 3 years on my daily driver.
Posted By: Quicktree
Re: Tips on making a rear end narrowing jig? - 11/22/14 12:25 AM
where do you get the shafts?
Posted By: Jerry Kathe
Re: Tips on making a rear end narrowing jig? - 11/22/14 03:57 AM
Quote:
where do you get the shafts?
I just rechecked this thread and the Ebay source posted above is not the one I used. The kit I purchased came with the 65” alignment bar and 12” carrier set up bar. All of the adapters were made of steel not aluminum. The housing end retainer's also use a thumb set screw and not a pinch bolt. I also remember it also came from somewhere in Texas. I looked in my Ebay transactions and couldn’t find them. Seems to me it was around 2005 when I purchased this stuff and it cost around 350.00 plus shipping for everything.
I have done a boatload of 9” ford stuff(all sizes of big and small carier and axle bearings) and several Dana’s but only a couple of 8.75 mopars and it has worked great. I also got the Olds stuff since Lamb engineering uses that size housing end on their stuff. I will keep looking and if I find the source I will repost. Sorry for the confusion.
Posted By: markz528
Re: Tips on making a rear end narrowing jig? - 11/23/14 05:51 AM
Quote:
Im a welder/machinist by trade but I still purchased my tooling, however I needed tooling for all brands. For your purpose I understand your approach. IMO; machine the adaptors the same OD as the carrier and axle races and the ID to plus .001 - .0015 of the alignment bar.
Welding....this is where it gets tricky....for the order, weld the back brace first then the pads then the ends.
Mig or Tig dictates alot about the process.
Just take your time and skip around allowing ample cool time is about all I can say...this is where experience cant really be clearly explained.
Thanks for all the responses!
That is very close to what I was planning on. Looks like the nominal outside diameter of the carrier bearing races is 3.2650 so that is what I will target for that donut, and I will measure the ID of the new housing ends and subtract 0.0005 to 0.0010 inches.
For the ID holes, I was planning on 0.002 inches clearance on the carrier donuts and 0.001 inches on the housing end donuts.
Sound reasonable?
We really would like to tack the pads on before we weld the rear brace. Is that a big or minor risk? Will the housing real twist enough to make the pad location an issue?
I am using a 2 inch bar, and really want to custom make my own donuts. I don't know what clearances the ones being sold use, and I am not too keen on their design.
I am planning on miging the rear brace and tiging the pads and housing ends. Does that make sense?
Posted By: Jerry Kathe
Re: Tips on making a rear end narrowing jig? - 11/23/14 03:33 PM
Thanks for all the responses!
That is very close to what I was planning on. Looks like the nominal outside diameter of the carrier bearing races is 3.2650 so that is what I will target for that donut, and I will measure the ID of the new housing ends and subtract 0.0005 to 0.0010 inches
For the ID holes, I was planning on 0.002 inches clearanceon the carrier donuts and 0.001 inches on the housing end donuts.
Sound reasonable? Yep. Just make sure that you also
maintain concentricity with ID/OD when machining the
adaptors - just as important as the tolerance itself.
We really would like to tack the pads on before we weld
the rear brace. Is that a big or minor risk? Will the
housing real twist enough to make the pad location an
issue? I see nothing wrong with that, could make it easier to assure ubolt clearance.
I am using a 2 inch bar, and really want to custom make my own donuts. I don't know what clearances the ones
being sold use, and I am not too keen on their
design.
I am planning on miging the rear brace and tiging the pads
and housing ends. Does that make sense? Sure - nothing wrong with that.
Posted By: jcc
Re: Tips on making a rear end narrowing jig? - 11/23/14 05:36 PM
"I am planning on miging the rear brace and tiging the pads and housing ends. Does that make sense?"
IMO, Not really, tigging compared to mig, will put a lot of heat into the rear, ie distortion, and take a lot of time.
Posted By: Jerry Kathe
Re: Tips on making a rear end narrowing jig? - 11/23/14 07:04 PM
Quote:
"I am planning on miging the rear brace and tiging the pads and housing ends. Does that make sense?"
IMO, Not really, tigging compared to mig, will put a lot of heat into the rear, ie distortion, and take a lot of time.
Actually you have that backwards. You can control the heat with a tig and still achieve fusion and penetration. With a mig the heat has to balance the feed.....moving faster will just reduce penetration. Tig is slower...but not a ton slower.
Posted By: jcc
Re: Tips on making a rear end narrowing jig? - 11/23/14 09:42 PM
We still disagree on the end result for the OP.
Posted By: markz528
Re: Tips on making a rear end narrowing jig? - 12/07/14 05:37 AM
Well I got the bushings done. Came out good - loosest fit is around 0.002 inches on the carrier donuts - the ends are tighter and feel real nice on the shaft.
As soon as the rear housing comes back from getting cleaned gonna give it a whirl!
Posted By: MR_P_BODY
Re: Tips on making a rear end narrowing jig? - 12/07/14 06:18 AM
Quote:
where do you get the shafts?
When I made my set up I had a 6' length of 1.250 hard
ground shaft laying around work that I used... I spun
up all the pucks out of alum.. everything has .0015
clearance
EDIT
work your way outward.. ends are last and if you
can run the back brace right out to the ends
Posted By: Jerry Kathe
Re: Tips on making a rear end narrowing jig? - 12/07/14 01:56 PM
If you welding skills are within reason of your machining skills, you will be fine. Good Job!
Posted By: SB412DUSTER
Re: Tips on making a rear end narrowing jig? - 12/07/14 04:21 PM
I went to WalMart and bought a gun bluing kit and applied that to the pucks so they would not rust as easy.
Posted By: moparx
Re: Tips on making a rear end narrowing jig? - 12/07/14 04:36 PM
and if you need to straighten the housing after welding, measure with 3' sticks of straight, stiff material clamped to the ends at 90* intervals. if out, keep the inner pucks & bar clamped into the diff while the housing is chained to a hefty piece of I beam. a touch of heat[plus wet rag quench] & a small bottle jack [12tonish or so] will put the housing into the correct place so the end pucks will zoom into the bearing bores easily on the center bar. this process description sounds lots more difficult than it really is.
Posted By: RobX4406
Re: Tips on making a rear end narrowing jig? - 12/07/14 07:20 PM
Nice work on the mandrels.
Posted By: CMcAllister
Re: Tips on making a rear end narrowing jig? - 12/07/14 11:43 PM
Rather than trying to fix it after it's welded or welding the ends on off center, I've been doing it a little differently. I fixture the housing and pull the ends of the tubes forward (away from the brace), fit the brace to the housing at that point and hold the bow while welding it. It's going to pull. May as well have it pull back to where it needs to be.
I don't actually bend the housing and pull it so far that it springs back to where I want it, I just pull it to where I want it and hold it there. The 9" and 8.75" housings have some flex in them before they are braced up. Easier to do it before than after the brace is welded up.
Keep the jig bar in the housing and use it to measure how far off from axle centerline you are moving it.
The amount you pull it depends on the width of the housing and the brace. The longer the weld, the more it needs to be compensated for. Maybe 1/4 or so on a stock length housing, less as it gets narrow.
Spend the time to get a tight fit on the brace. Relying on filler to take care of gaps will make the pull worse.
Posted By: markz528
Re: Tips on making a rear end narrowing jig? - 01/20/15 01:53 AM
Well you all scared me about how much it is gonna move so I ended making a jig. Its as good as I can make it, so if it moves I will use the jig to straighten it.
Back brace is pretty much ready to get welded.
Posted By: markz528
Re: Tips on making a rear end narrowing jig? - 01/20/15 01:56 AM
Having trouble with picture. Lets try this.......
Posted By: MR_P_BODY
Re: Tips on making a rear end narrowing jig? - 01/20/15 02:11 AM
Just weld short spots at a time and jump around..
do some on the left... jump to the right side and
let it cool. if I can put my hand on it with my light
gloves I'll burn there.. just jump around
Posted By: Monte_Smith
Re: Tips on making a rear end narrowing jig? - 01/20/15 02:33 AM
Quote:
Well you all scared me about how much it is gonna move so I ended making a jig. Its as good as I can make it, so if it moves I will use the jig to straighten it.
Back brace is pretty much ready to get welded.
Your back brace is too short. It WILL bend out on the ends with the brace that short. You obviously have fab skills. I suggest you run the brace as close to the ends as possible and then "tube" the brace for the U bolts
Monte
Posted By: markz528
Re: Tips on making a rear end narrowing jig? - 01/20/15 02:43 AM
Quote:
Quote:
Well you all scared me about how much it is gonna move so I ended making a jig. Its as good as I can make it, so if it moves I will use the jig to straighten it.
Back brace is pretty much ready to get welded.
Your back brace is too short. It WILL bend out on the ends with the brace that short. You obviously have fab skills. I suggest you run the brace as close to the ends as possible and then "tube" the brace for the U bolts
Monte
Monte - I was thinking of adding some end pieces that overlap the short brace by about 12 inches and bring it as you said, as close to the ends as possible. Do you think that would be effective?
Posted By: Monte_Smith
Re: Tips on making a rear end narrowing jig? - 01/20/15 03:12 AM
Quote:
Quote:
Quote:
Well you all scared me about how much it is gonna move so I ended making a jig. Its as good as I can make it, so if it moves I will use the jig to straighten it.
Back brace is pretty much ready to get welded.
Your back brace is too short. It WILL bend out on the ends with the brace that short. You obviously have fab skills. I suggest you run the brace as close to the ends as possible and then "tube" the brace for the U bolts
Monte
Monte - I was thinking of adding some end pieces that overlap the short brace by about 12 inches and bring it as you said, as close to the ends as possible. Do you think that would be effective?
Outside the perches is where it will bend...........needs something to support it
Monte