2nd Gen Non-Engine/Transmission D70 - 93 rear (complete axel) replacing my D70 - 99 what to expect?

[Joe Mc]

Some of you may not have seen my thread https://www.turbodieselregister.com/forums/showthread.php?237151-D70-Snagle-Tooth which leads to my new find, the above thread title and questions below.



So, I scored a D70, 3:54, Power Lock complete drum to drum for $300!!!! It was a crusty critter, but upon removing the cover everything checked out good so I loaded it up and got it home. Further inspection once home revealed the power lock unit had a 10 03 93 stamping on it 10/3/93 build date I'm guessing, which went right along with the sellers description that it came out of an early 2nd gen. The best part is I noticed the ring & pinion were hardly worn and the wear pattern was dead on but hardly noticeable. Further inspection of the numbers stamped on the side of the ring gear displayed 03 08 03 once again 3/8/03 build date for the ring and pinion I'm guessing. So, at this point I'm rather pleased with my $300 purchase. The diff cover had some pretty nasty chunks from the previous internals letting go, most likely ring and pinion gears chunking off? Presently the rear has been stripped of the axels, floating hubs, brake plates, old lines and all the rust with two coats of etch primer followed by two coats of black finish paint. I plan to use my brake plates and drums maintaining the axels and hubs from the 93. I may pull the 2 year old bearings and races out of my hubs and install them in the 93 unit, but I'm not sure about that yet? The one's in the 93 look like they were changed around the same time the ring & pinion were, I'm thinking if it were me sinking in a ton of cash on a new ring & pinion and since it had to come all apart I'd probably install new clutch packs and inner bearings as well, by the looks of the hub bearings they appear to be as new looking as the ring and pinion. If my hunch is correct on all this I think I just spent a pittance for a great deal on something someone sunk quite a bit of cash into and then unfortunately wrecked the truck or ? And the rear has been sitting outside the sellers house for a few years. He said he bought the front & rear units along with an X-fer case as a package some years ago and only intended to use the X-fer case and front unit.



Now here's the nature of the above title: There's a speed sensor in the top of the diff, but no tone ring. I can't remember if the rear in my truck has a tone ring or not? It definitely has the speed sensor, should I use the speed sensor that's in my old (99) rear or keep with the one in the 93 rear???



So, I'll certainly find out if there are any issues once I swap the rear out, but was wondering if I'll be throwing anti-lock codes (RWAL only) and/or will I have a speedo or not once the new (93) rear goes in?



Any other things I should be aware of relating to this swap of an earlier rear into a later chassis? Please share your thoughts.



Thanks guys and gals.

 

[Joe Mc]

So here's what I've found out so far re: 93 rear going into a 99 truck.

1). It will “fit”, but the 93 has shock bracket/mounts that are angled down a few degrees and the holes to bolt up the sway bar are a bit too wide or narrow. The shock/sway bar brackets on the 99 are level = not angled down. I’m guessing I’ll be cutting off the shock/sway bar brackets from both rears and welding the 99 ones to the 93 rear? Not quite sure at this point?

2). The 99 does have a tone ring for Anti-lock (RWAL) and Speed sensor. I'm hoping I can just use the speed sensor from the 93 rear that doesn't have a tone ring and at least have a speed-o-meter. I'll most likely end up with an Anti-Loc code hopefully that's the only code - if not and there's no speed-o-meter then I may be forced into limp home mode and be screwed, or have something electronically to figure out? I might try just using the 99 sensor and see what happens first, as I'm not sure if the 93 sensor will connect up to the 99 wiring harness yet? As far as the RWAL functioning I could car less it always seems to activate at the most inappropriate time and almost causes me to hit something.

3). The 99 and 93 floating hub area on the axels differ slightly. All the measurements are the same for: the seal surface, length of the tube from end axel plate to end where the nut goes on, bearing diameter surfaces, and the brake plate diameter and bolt pattern are the same. The only difference is the 93 has a bit of a taper from the flange where the brake plate bolts on to the area where the hub seal rides, whereas the 99 has no taper. This shouldn’t be a problem either way as I could use the 99 or the 93 floating hub assemblies.



I would have been done with the swap this weekend, but when you have rusty things (springs, mounting spacers, u-bolts and the like) that can’t be addressed with everything bolted up, the best course of action is to address while it’s all apart. Unfortunately I ran out of etch primer and still had one overload spring to prime. So, the work will continue after work (my real job) this week as time permits. Lucky my daughter isn’t going back to school until the spring and I can use her car to get to work – I can’t wait to get out of her timid 99 Taurus and get back into my truck.



More to come.

 

[HHhuntitall]

Sway bar is trivial. So this axle has 3" wide spring pads at the correct spacing? Very interesting. As for the shock mounts, that's not a problem, weld 'em where you want them. The speedometer is going to be a major problem for you, though. The field generator used on the '93 style axles is not going to work with the magnetic signal generator. You'll need to try to find a way to use the '99 sensor, if possible. This rear doesn't have a tone ring on the ring gear?



The ABS code is a "soft" code, and won't trigger engine reduction of power. My '98 is doing the same thing right now, with a mesquite limb hanging rather obviously from between the frame and front of the fuel tank..... My guess is it broke the wires going to the sensor on the rear..... Anyone know what the ohm range difference is on the sensors?

 

[Joe Mc]

I must communicate that I incorrectly stated the rear is from a 93 truck. The power lock unit has a 10/3/93 build date so this (part built in October 93 conceivably went into a 94 truck as we all know they don't wait until the model year to build them) would coincide with an early 2nd gen of 1994.

I cut the shock/sway bar brackets off my 99 unit and the 94 unit then welded the 99 brackets on the 94 and installed the rear. Yep the 94 rear is minus the tone ring and regardless of which sensor I use there's no speed signal. At least with the 99 sensor I get no ABS, Brake and Check Gauges lights. I thought I wouldn't have a speedo but was hoping things might work out - so much for "Hope". The other un-anticipated bummers are: no cruise control and no auto lock at 15 mph. At least the trans shifts correctly and into OD so I'm road worthy.

I just need to figure out how to get a speed signal and send it to the ecm in a language the ecm can understand.

Any ideas would be greatly appreciated.

Thanks for reading.

 

[HHhuntitall]

Hmmm... . I'm gonna have to think on this one..... Does it have the holes for the tone ring in the ring gear?

 

[cerberusiam]

You are probably going to have to swap in the 99 tone ring to get it to work correctly. There is a major difference between the signals each generates.

I am surprised you get OD and good trans shifting. Evidently wheel speed is not as critical as it is the later trucks.

 

[HHhuntitall]

The only other source I can think of to find a signal would be a early speed sensor on the tailhousing of the transmission, like the older trucks... . I'm not sure how those signals pulse... I know they're a field generator... . Can that signal be converted to work with the later computer?

 

[Joe Mc]

OK guys here's what I found out the other day. Although Dodge Ram Shop Manual (not Chilton's or other) states a case spreader is required it wasn't needed.



I had my old (99) rear out and on stands, with the axels out and cover off I removed the caps holding the open end assy in place to the housing and rolled the housing so the gear was facing down and "plunk" out it came. Since this rear was scrap I decided to explore a bit more, I removed the 10 or 12 bolts that hold the ring gear to the carrier flipped it over and tapped the whole thing on the ground and off came the ring gear. Further examination of the tone ring revealed it just sits on the carrier = not bolted as I thought it would be with the ring gear to the carrier? The carrier has a notch where a tab on the tone ring sits then the ring gear simply covers the notch on the carrier. Interesting. So I took a plastic/rubber hammer and tapped the tone ring, off it came!



So, I'm thinking of removing the cover on the 94 rear that's in my truck to try and "see" if there's a notch on the carrier. If not then I may explore cutting a notch. Of course I'll check diameter comparisons before screwing anything up. If all looks to work out I'll see if the power lock assy comes out as easily as the open end one did. Maybe I'll get lucky? Plan is, "if the locker unit's outside diamete measurement matches the inside diameter of the tone ring", mark the caps that hold the locker to the housing, remove bolts, remove locker, mark ring gear to locker unit, test tone to locker fitment by "eyeball and measurement", if all looks well break out the grinder and cut a notch, install tone ring, ring gear, locker, axels, cover, fill with lube and see what happens.



I "may" just get lucky for once in my life. Of course this plan wont be executed until I install the 2nd new heater core in 2 months first, gotta have heat. Oh, if you guys haven't read the other thread I started about replacing the heater core and evap - I'll give you a tid bit: Don't buy your heater core and evap from Dodge, they're made in China and Twain and the better part (evap) is made in China, heater core was made in Twain - leaked upon installation. I'll be certain to test the new (provided by Dodge to replace the POS they sold me the first time) heater core before I even think of removing the dash "AGAIN!!!" - rant complete.



More to come about the rear. Oh, the 94 housing does have hole for the speed sensor and the 99 sensor is installed presently with no speedo, cruise or auto lock at 15 mph.



Wish me luck guys . . .

 

[cerberusiam]

no auto lock at 15 mph.

What does that mean?



Does the lockup clutch work at all or just not when it used to?

 

[Joe Mc]

The 94 rear that I installed in my 99 truck works perfectly. The situation is there's no tone ring on the 94 rear to communicate with the electronics on my 99 truck which is why I have no speedo, cruise, odometer increase and no "door-lock" at 15 mph as before. There's nothing wrong with the 94 power lock complete rear (drum to drum) end that I installed in my 99/

 

[cerberusiam]

I understand mechanically there is no issue. A rear end that will bolt in would work.

The problem you are having is you have no wheel speed signal. That will impact multiple systems as you see, CC, door locks, etc. Auto-lock was confusing, I did not know if that was transmisison related or something else, hence the question.

I am surpised your transmission works as well as it does, if at all. The later trucks are dependent on wheel speed for certain ECM, PCM, and TCM functions. Youu loose wheel speed signal you loose trans control, get engine derate, etc.

As I said previously, you will need to get the correct tone ring on the existing carrier to generate the correct signal for the wheel speed sensor. There is a difference between a 94 signal and a 99 signal, hence your problems.

I was questioning whether your TC locked up correctly and trans operation was, for sure, correct. That is what I thought you meant by auto-lock.

 

[CCiatteo]

https://www.turbodieselregister.com...ion-G56-(pictures)&highlight=speed+conversion

Could this dakota digital box be *******ized somehow to solve the problem?

Chris

 

[Joe Mc]

I understand mechanically there is no issue. A rear end that will bolt in would work.



The problem you are having is you have no wheel speed signal. That will impact multiple systems as you see, CC, door locks, etc. Auto-lock was confusing, I did not know if that was transmisison related or something else, hence the question.



I am surpised your transmission works as well as it does, if at all. The later trucks are dependent on wheel speed for certain ECM, PCM, and TCM functions. Youu loose wheel speed signal you loose trans control, get engine derate, etc.



As I said previously, you will need to get the correct tone ring on the existing carrier to generate the correct signal for the wheel speed sensor. There is a difference between a 94 signal and a 99 signal, hence your problems.



I was questioning whether your TC locked up correctly and trans operation was, for sure, correct. That is what I thought you meant by auto-lock.

I now understand your question and confusion with the "auto-lock" in my thread. Silly me, auto-lock - yep that could be a term for a myriad of things. Sorry bout that.



I'm surprised the trans is shifting too? I'm guessing there's some sort of signal getting from the 99 sensor that's installed in the hole on the 94 rear where the 94 sensor was. Interesting that the 94 rear sensor just picked up some signal, I guess from the tips of the ring gear teeth? Who knows? Anyway the 99 sensor must be picking up something from the tips of the ring gear teeth as well because when I installed the 94 sensor, and test run the truck on stands, I immediately had: ABS, Brake and "check gauges" illuminated on the dash. These alarms all went away when I plugged in the 99 sensor and tested?



I'm just glad that I can drive it and the trans shifts. I was anticipating that if I couldn't figure out the no tone ring deal that I may be stuck in limp home mode and not be able to drive. So this at least gives me my driver back until I can figure out the tone ring/signal deal. I'm hopeful that the 99 tone ring I removed can be easily installed on the 94 power lock unit. More to come on that, as soon as I get done installing the 2nd new heater core #@$%!. At least I was able to get the dash laying on the front seat before loosing light and the cold came in last night. So I'm off to get it back together today and hope to check out rear situation tomorrow.



Thanks for reply.

 

[Joe Mc]

Got it figured out and fixed ! ! !

OK so for those who are following this here's how it went.

Keep in mind I'm working w/regular hand tools in my driveway.

-I removed the sway bar, diff cover and used an outside caliper to measure the diameter of the power lock carrier next to the ring gear, anticipating if the size was the same as the inside of the tone ring that I'd have to cut a groove in it for the tab on the tone ring to land into.

-I was disappointed that the new oil was so dark and was shocked at all the metal-flake I saw - more on that as we progress.

-The dimensions were exact, the tone ring was a tad smaller.

-I marked the Bearing caps L/Top & R/Middle, removed the bolts and with a little finessing (small pry bar and about 10-20# force) on a bolt on the power lock unit and then on a bolt on the ring gear, alternating with each little movement of the unit. I was able to get the unit free and loosely laying in-side the housing.

-Wrestled the unit out and placed on a work surface, I noticed a notch was present on the carrier Oo. so I zinged off the ring gear bolts, and tapped the ring gear w/plastic hammer.

-Laid the tone ring in position and with the plastic hammer gradually tapped the tone ring home going around the circumference of the carrier. "that was easy".

-Now that I knew the whole deal would work I started to investigate the metal-flake previously noticed . . .

-There appeared to be some nicks on 3 of the 13 vanes/ridges running from the center to the outside diameter between the bolt holes where the ring gear bolts to the carrier, the 3 with nicks have areas stand further away (closer to the housing internals) than the others. These 3 have almost like a lug on the outer edge (hard to explain) that's rectangular - about 1/4" wide X 5/8" long and stands about 1/16 or so proud of the other vane/ridge ends (like I said-hard to explain). The other 10 are level with each other and rounded as they come to the outer edge.

-Also, one of the bolt heads looked a bit ground off on a flat that was situated on the outer diameter

-I inspected the inside of the housing and saw scrapes & grooves and a couple of pretty decent nicks in the upper left (driver-side) area close to where the sensor protrudes into the housing :{

-I decided to grind off the protruding areas on the 3 vane/ridges mentioned above leveling and rounding the edges to look like the other 10.

-With a die grinder I smoothed off the areas inside the housing, protecting top area where there's an oil inlet that supplies the pinion gear bearing.

-I then used solvent & air to clear out all the debris, utilizing a magnet to pick up all the debris that wouldn't come out of that wonderful little pocket at the bottom of the housing.

-I then returned to clean up the assy blowing air from the center towards the outer edges. Before I started grinding on these 3 areas I protected the bearing and ring gear side of the assy with painters tape and news paper.

-I installed the ring gear (previously marked with a paint pen to properly relocate exact position) to the assy, snugging two bolts 180* from each other and then hand tightening the remaining 10 bolts.

-Now the fun began - torquing the ring gear bolts. They're to be set at 120-140# according to the shop manual. I had to use a bigas pry bar carefully inserted into one of the slots on the assy to hold the whole thing still. Also, according to the shop manual - "torque bolts evenly" - yep no sequence or other guidance. So I decided since there were 12 bolts I'd work 6 at a time in 2 triangular stages then move onto the other 6. I started at 60# made the sequence then bumped the clicker up to 140#, boy that was fun=not.

-I decided to check the torque on the bolts holding the two halves of the power lock unit together and found one out of spec by about 1/2 of a turn I think these were to be torqued to 80# but check the manual to be sure. Disclaimer: "Don't pay too much attention to the writer as his memory just ain't what it used to be . . . "

-I wrestled the assy back in place and had to finesse the bearing races back into the saddle area, once again the plastic hammer and working one side to the other proved effective.

-Installed the bearing caps, a little each side until the bolts would start, of course plastic hammer, and then turing the bolts in each time the cap moved into place a little bit more until finally they were sitting home on the case flats.

-I snugged the caps and as the manual recommends, to seat the bearing races solidly into the housing/caps, I tapped the ring gear with a dead blow hammer to seat the right race and then the edge of the power lock to seat the left race.

-Torqued the cap bolts - once again no reference other than torque to 80# (don't forget previous disclaimer). So I did the torque in 3 stages 20#, 50# and then final.

- I put the rest of things together, added oil, installed wheels, sway bar, etc. And headed for the open road.

-Speedo works, auto door lock at 15mph is back on line as well as the most important device = the Cruise Control



So, then moral to this story is: If you can find the specific year replacement rear for your truck that would be the easiest. If you can't find an exact replacement, as long as there's a sensor hole in the housing (if you need one), you can make it work with a good deal of work.



Man, I'm glad that's done, and I finally reinstalled the 2nd new heater core all I need to do now is charge the A/C "again". Oh, the wonderful folks at the Dodge dealer never credited my card for the second heater core oh yeah I'm and will be calling them Monday#@$%! Most likely for the last time unless I can't get what I need anywhere else, or if I think I should pay 2-3 times more for the same off-shore parts I could get at the auto stores = no chance in hell!



I hope this post/thread was, or might, be helpful to one of our brothers or sisters out there.



Joe Mc

 

[HHhuntitall]

Good to hear. Nothing like working on your own junk!!