2nd Gen Non-Engine/Transmission Open carrier to LSD Power-Lok in my '01

[Eric Lee]

I am scheduled to have a LS (Power-Lok) diff. installed in my D70 truck on 11/21/05 and would like to hear any advice or special instructions for my trans. mechanic - Dave at L&V in Kalamazoo - (I think he is probably the best around here, is very fair and understands our upgrades. )



Searching threads I've picked up on plate stacking - modifier amount -

problems with long term operation and whatever -



Anybody have a favorite plate configuration out or a system to judge when there's 'just enough' modifier in there?? Anything special about this install, or just do it by the book?



- Eric Lee

 

[B KIRK]

Eric, go to THIS post, and print it. Take it with you to show to your installer. If he understands our mods, he should know what would work best, for the results you want.



Brad

 

[Eric Lee]

Brad - Thanks for your efforts -



I see by your photo gallery and suspension mods that you're probably a fellow fabricator. Nice work - I see you came up with some real innovative ideas.



- Eric

 

[Fishin Guide]

I have a Powr-Lok in my truck. I would recommend that you NOT resatck the clutches. They are pretty grabby stock, much more so than the Trac-Lok.



I used just under 1-1/2 ozs of ford motorsports friction modifier to get the best results. Now, It'll black stripe evenly under all conditions and has no grab in dry corners. Wet conditions do scrub the tire slightly depending on the surface.



The install will vary a little depending on if you are replaceing the ring and pinion at the same time. This has mostly to do with bearing preload, but anyone that has set up gears will understand that already.



I like to take it easy on an install and let the fibers work in. The first 500 miles or so, the fluid should be changed. This will get rid of all the little loose particles.



I like synthetics, but with this rear end, it can be tricky to get the friction modifier right. Many of them have the friction modifier "built in". Often, it is way too slick or very grabby. So, friction modifier should be added sparingly.



A good quality gear lube has run cool and the clutches are also looking good. And I barely get anything on the Mag-Hytec magnet.



Dave

 

[Eric Lee]

I'm wondering what configuration the diff was shipped in. My guess is the clutches are stacked with 3 friction surfaces from the factory. Do you think it's necessary to take it apart to verify?



Dave - I think I will take your advice and not restack for more friction at this time. I do tow alot -



I am trying to make sure I compile all the parts and info I need before next monday - I ordered the Master Install kit - at 60K miles it probably doesn't need everything replaced but when the order taker at Randy's added it to the bill I didn't object.



Do the axle nuts come off during this procedure? I believe DC uses one time use nylock axle nuts on these? Is there anything else I will need?



Thanks - Eric

 

[B KIRK]

Thanks Eric. Went to your website. Nice. I would never have the pactience to do that kind of work.



On the stacking of the clutches, that info is right out of a Dana-Spicer book.



I have opened some Powr-Loks that came stacked different than others. Also, some have the friction plates lined, and some are not. Even ordering new clutch packs, same part number, sometimes they are lined, but usually not. The ones I get that have the lining on them, I send back. With the concave shape of the disks, the surface contact area is minimal. It quickly eats the lining off, ending up metal to metal. All the lining does is get mixed in with the fluid, then gets to the bearings. A magnet won't pick up the lining material.



Also, the stacking order that may work in one truck, might not work in another.



Things like gear ratio, tire size, power level, weight of truck, etc. can all contribute to the load on the clutch pack.

Best thing to do is look at the stacking order in the link, and see what yours is when you get it. Determine how tight you would like the unit to perform. Then go from there.



Things to consider with a Powr-Lok. When there is a load on it, the spider gears are on a ramp that puts more pressure on the clutches. But on snow, or slippery surfaces, there is sometimes not enough traction to put a load on the spiders to make them tighten. That is the reason to stack them for your use.

If you read the last page, it tells you the difference in torque to break one side loose. Of course, that is without a load, from the spiders, on the clutch pack.



You don't have to remove the axle nuts. Just the axle shaft.



Brad

 

[Eric Lee]

I spoke with Randy's R&P today and the tech said the diff probably was shipped with alternating discs (5 friction surfaces). He recommended, especially with the diesel, to leave them that way.



I asked about all steel clutch packs - he looked up the part number and found them to be discontinued by Dana.



He concured with you about the mess fiber clutches make in the gear lube - unless there is someone out there making aftermarket clutches - it's the fiber ones for now.

I'll replace the lube after 500 miles and hope for the best.



We got our first snow yesterday (1-2 in) so it looks like my timing is right on this project-



- Eric

 

[Eric Lee]

Got it in yesterday - I have read here to take it easy for the first 500 mi so I haven't had a chance to really test it out. I can't tell a noticeable difference in the few miles I've driven it - no grab in the corners - no unussual noises. I did get on it a little on the way out of the gear shop's drive before I remembered about the break in and it was definately putting more power down on the heavy outside wheel.



I really love this truck - I'm sure after I get to know how this LS works and what to expect I'll love it even more.



I'll post here when I get to stretch her legs in a few more miles.



As a side note I had him service the transmission (new filter, fluid and adjust the bands) since it's been 15K since the Suncoast stuff went in and he put in Royal Purple. I'm think that its making the trans shift a little different - not a bad different but different.



-Eric

 

[Eric Lee]

Well ... ..... I have to say the truck has a whole different personality in 2wd. The little snow we got over the last couple days has been a nice test.



Pulling up to a stop there is more attention needed to the brake pressure applied. With the torque the Cummins puts out, unless you fully press brake at the full stop, both tires spin and the back of the truck will shift unlike the open diff that stayed in a straight line and just spun one tire. Also pulling out of same intersection, there is a little more attention again required not to 'shift over'.



I needed to run some railings to the sandblaster (that incidently I have to install tomorrow - Thanksgiving - to make my deadline) who has a pretty steep drive. In the snow, with a 15 - 20 % incline, with a trailer (2600#) in tow, she came right out. No 4wd. I was pretty impressed.



I guess the posi burn out will have to wait for Spring. Honestly - I have never done a burnout with this truck - not really - with the big clouds of smoke and chips of rubber flying. So I probably won't be now - but I do like the new abilities she has now.



I think my mechanic put in a touch too much modifier (2-2. 5 oz total) only because I feel and hear very little difference in a turn on dry pavement. I think when I do the 500 mi oil change I'll sneek up on it to get just past the hard grab.



And to confirm the cost - $770 for all the parts - $300 Labor.



If you have an Open Diff and have had it for a while - you will wonder the same thing I am if you change it to LS - 'why did I wait'. I guess the grand it cost was enough reason for me -



-Eric

 

[Eric Lee]

I've had this unit in for 700 or 1000 mi now and I am still happy as a pig in doodoo. It is so nice to have both tires working now.

It's time to flush the break-in fluid and the fluid Randy's shipped is just not to be found here in Kalamazoo. Pennzoil GL-5 80/90 GearsPlus - I had to call Randy's and have them ship me 4 more bottles (plus 4 for next time). I also ordered 2 more bottles of Ford Motorsports Modifier.

They told me that the PowrLok in this dif requires 4oz - only racing applications require less. The reason being that with less modifier the clutches lock and unlock instead of slip as designed. I was running 2. 5 and liking it with no chatter, just a little grabby on tight turns.



So if your doing this mod - order extra fluid as it might not be available in your area -



-Eric

 

[B KIRK]

Glad it worked out for you. Just keep an eye on the fluid and it should work great.



Brad