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27 or 29 spline 8.25 rear end?

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Old Aug 13, 2009 | 05:22 AM
  #1  
Dan4governor's Avatar
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Year: 1996
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Default 27 or 29 spline 8.25 rear end?

I have a 96 cherokee sport with the 8.25 rear end. I'm gonna change the fluid today and I was wondering while I have the dif cover off, how can I tell if its 27 or 29 spline? I know it sounds stupid, but I don't really know what a spline is. Any pics would help.
Thanks,
Dan
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Old Aug 13, 2009 | 05:50 AM
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Pretty sure the 29 spline started after 98...so you should be 27.
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Old Aug 13, 2009 | 06:19 AM
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1996 is the cut off year. Particularly if you have a "late build"



50-50 chance you could have either spline in that case.



Gotta pull the shaft to count. I suppose if you could clean and mark one spline, you might be able to count them while it's still in the spider gear.


BUT .... I'll bet you end up counting 28 splines.






Joe
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Old Aug 13, 2009 | 07:10 AM
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97+ are all 29 spline. Late year production 96 are 29 spline.
The only way to be cerain is to count the splines on the shaft itself.
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Old Aug 13, 2009 | 12:05 PM
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Sorry to hijack, which one is stronger? Ive heard the older 8.25s are, just wanna make sure
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Old Aug 13, 2009 | 12:14 PM
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Originally Posted by flexinxj
Sorry to hijack, which one is stronger? Ive heard the older 8.25s are, just wanna make sure
the newer 29 spline are stronger
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Old Aug 13, 2009 | 12:25 PM
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27 spline 8.25s have a 1.17 diameter axle shaft
29 spline 8.25s have a 1.21 diameter axle shaft
Dana 35s axle shafts are 1.18 diameter

The only strength gain a 27 spline has over a D35 is the axle housing being larger diameter with a thicker tube wall.

Of all the 8.25s I have seen in junkyards, I have noticed a slight variance in the yokes that may be a factor in identification. I have a 27 and a 29 spline in the garage and will post pics of the yokes when I get home this evening.
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Old Aug 13, 2009 | 08:38 PM
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These are the two different yokes, the left one is from a 27 spline and the right one is from a 29 spline 8.25. The 27 spline has the collar around the base and is a bit shorter than the 29 spline.

Disclaimer: This is just a difference that I have notice and should not be used as a rule for axle identification. I'm just saying that every 27 spline I have seen has the shorter yoke with the collar, and every 29 spline I have seen has the taller yoke. And NO, I have not seen every Chrysler 8.25 axle. The difference may be solely due to a change in design during the 96 model year because I have seen both yokes styles on 96 model XJs.

Name:  Chryco 8.25 yokes 002b.jpg
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27 or 29 spline 8.25 rear end?-chryco-8.25-yokes-003b.jpg
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Old Aug 13, 2009 | 08:48 PM
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Originally Posted by CrawlnCoupe
the newer 29 spline are stronger

thanks, appreciate it


flexinxj
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Old Aug 13, 2009 | 08:56 PM
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Originally Posted by winston427
These are the two different yokes, the left one is from a 27 spline and the right one is from a 29 spline 8.25. The 27 spline has the collar around the base and is a bit shorter than the 29 spline.

Disclaimer: This is just a difference that I have notice and should not be used as a rule for axle identification. I'm just saying that every 27 spline I have seen has the shorter yoke with the collar, and every 29 spline I have seen has the taller yoke. And NO, I have not seen every Chrysler 8.25 axle. The difference may be solely due to a change in design during the 96 model year because I have seen both yokes styles on 96 model XJs.



Nice work!


I don't think I've ever even paid attention to that.




Joe
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Old Aug 13, 2009 | 09:04 PM
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Originally Posted by EndlessMtnFab
Nice work!


I don't think I've ever even paid attention to that.




Joe

I pulled a yoke off of a 96 at the jy last weekend to replace the one I damaged the last time I wheeled the XJ. It had a production date of 12/95 (fairly early in the production run) and had the later style yoke. That's what makes me wonder if it is just a design change and not a determining factor in spline count. I plan on going back this weekend and pulling a shaft to count the splines. If it is 27 then we can throw this whole concept out, if it is 29 then I will have a set of trail spares coming home wtih me.
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Old Aug 14, 2009 | 02:12 AM
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Are those the yokes that connect to the drive shaft? If so I don't have to take anything apart to find out which one I have.
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Old Aug 14, 2009 | 08:26 AM
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Those are the yokes for the rear axle pinion. Like I stated earlier, this has not been determined to be a factual identifier.
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Old Aug 14, 2009 | 11:14 AM
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Subscribed. Thanks for checking into this. I'll be eyeballing the yoke on my 96 when I leave work today and then waiting to see if this is confirmed. I think mine had a 3/96 build date.
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Old Aug 14, 2009 | 12:08 PM
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Can somebody post a pic of where to look for the yoke? I dontknow much about axels.
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