POWR-LOK Research

how did you determine this unit was used with 4:27 ratio ?
it could have been used with any of the low gear ratios in my opinion.

 

jpflat2a,

If this particular Powr Lok was original to Jeep, a Jeep CJ model to be specific,
then it had to be the 4.27 ratio. 4.27 was the only axle ratio available in 4/63 for CJ models.
http://www.film.queensu.ca/CJ3B/Photos/Tech/ServiceBulletins/SB601AxleRatio.JPG
Well I should correct myself here... the 5.38 ratio was still an option in 1963.
I was told this particular Powr Lok was on a CJ-5 and so I suspect that its original application was likely a 1963 CJ-5.
In part I estimate this from the build date of 4-29-1963.
I don't imajine these locking differentials sat in stock inventory a long time before installation.
For my purposes it really does not matter what the specific ratio was.
Nor does it matter if it was from a CJ-3B, CJ-6 or 4X4 SW because this Powr Lok is good for any 3.92 through
5.38 gearset used in any Spicer 44 having 19 splines.

But I do like to know the history of what I am using.

Is it possible to determine the exact original application ???
Perhaps we can decode some of that information from the various Spicer numbers used.

I am quite familiar with all of the many various Powr Lok part numbers as were issued by Willys Motors Inc.
Those part numbers are recorded in the various Jeep parts lists and parts catalogs.
From that system, many various part numbers are used to identify the various Powr Lok differentials from 1957 through 1971.

Just to throw in some new input I will explain to those who are wondering how the Trac Lok differential fits into the picture.
The Trac Lok units are very similar yet not normally interchangeable with Powr Lok. The Trac Lok uses a 1 piece case and also different system of friction discs.
The Trac Lok differential is specific to Spicer model 44 rear axles using the 30 splined flanged axle shafts.

I guess I could go on and explain some about the variations found with Powr Lok units.
The very earliest Powr Loks used a cone type of friction arrangement.
Later Powr Loks came with flat friction discs then finally they came with curved disks as most Powr Loks are.
I would have to look at my Powr Lok notes to shed light on the specific dates for those changes.

Sorry I'm getting long winded again. Thanks Folks !

 

Another old school trick is to shim the clutch plates with carrier shims, or whatever shims you can find that are roughly the same diameter as the clutch disks. I shimmed the PL in the Dana 30 in my 75 17 years ago and it's just getting to the point now where I need to think about new clutches. You can actually turn them into a spool if you shim too much. Once you go through the trial and error of finding the shim thickness that suits your driving style it works really well. I think I shimmed each side about 10-15 thousandths (but honestly it's been so long I don't recall). I was going for more aggressive performance and I got it. The downside is that it didn't steer worth a hoot at first till the clutches got broken in a little. The thing I've always liked about the PL (particularly in the front) is that when you get the front end crossed up in some big rocks the clutches will give a little instead of an axleshaft doing so...
Anyway, it works for me...YMMV

 

another trick to make it more working is put a automatic transmision
oil in the diff. the thin oil makes the LS more working, i have done this
for years in my bronkoII, liberty and tj

if i would have a pl im my front axle i would do it again, it works after a few miles great

gerald

yes, i look for a PL

 

I just checked Amazon for Jim Allen's book on Differentials. You can get a used one for $150. yikes!

 

That's nuts. I went to www.ringpinion.com and it is out of stock. I would backorder from them and save the $120...
http://www.ringpinion.com/ProductDetails.aspx?ProdID=6660

 

I got mine thrown in for free with my last Randy order. Great book!

 

That's how I got mine as well.

 

Do you like your POWR-LOK? If so, thank the inventor Perry Hartupee

http://www.google.com/patents?id=DV...cted_pages&cad=2#v=onepage&q=powr lok&f=false

 

hello

Sparky

the link for the manual is broken. do you have a new link for the manual.

...

Re: POWR-LOK Research

http://earlycj5.com/tech/axle/Powr-lok/powr-lok.pdf

It's big though.


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