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Dynatrac Front Axle For the 94 Ram
WooHoo! A HD front axle with manual hubs!
|NOTE: Dynatrac now has a manual hib conversion for the Ram that uses the existing axle.|
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for Truck accessories.
Although I had never experienced a failure
or a problem with my front axle, I was never happy with the axle capacity,
Dana 44 axle shafts, the hub bearing arrangement, and the lack of manual hubs
(kit now available). If something went wrong in the front
axle assembly, there was no way to keep the axle shafts from turning and making
the problem worse. Also: the bearings use the outer axle stub for preload;
it impossible to drive with a broken or missing outer stub. Several Ram owners
have attempted to drive without the stub and all reported that the truck went
only a few miles before the wheel bearing failed completely.
After 4.5 years of grumbling about the weak front axle and the Center Axle Disconnect system used on my 1994 Ram, I finally decided to do something about the "problem". Dynatrac was founded in 1987 to provide individuals and small businesses with a dependable source for high quality drive axles. They quickly established a reputation as one of the best custom 4X4 axle builders, and can build heavy duty front and rear drive axles for almost any vehicle configuration. On July 29, 1998 I contacted them about building a new front axle for my 94 Ram. After a lengthy phone conversation where we discussed options, I ordered a new axle.
|Dynatrac Replacement||Original 1994 Ram Axle|
|Dana 60 reverse cut housing||Dana 60 straight housing - turning backwards|
|3.54 ratio||3.54 ratio|
|HD Warn manual hubs||Center axle disconnect|
|5200 pound axle capacity||4850 axle capacity|
|Standard, easily replaceable tapered roller bearings||pressed bearings - not serviceable|
|Replaceable Brake Rotors||Replaceable Brake Rotors|
|ABS compatible||ABS compatible|
|30 spline outer axle shafts.||30 spline axle shafts. 1.31"dia|
|Spicer 1480 axle cross joints. 1.375" cup, 3.000" Cross|
|HD dual piston brake calipers||HD single piston brake calipers|
|12.0"x1.25" Brake Rotors||12.0"x1.50" brake rotors|
|HD 1/2" thick alloy steel axle tubes||passenger side weakened by cast CAD housing|
|ARB air locker installed||open differential|
|Spicer 1350 U-Joint 1.188" Cup, 3.622" Cross||Chrysler 7290 U-Joint. 1.125" Cup, 2.625" Cross|
The reverse cut housing had another advantage - the pinion moved upward 2 1/4". A high pinion improves the driveline angle, provides better ground clearance for the u-joint, compensates for the taller springs up front, and reduces double-cardan joint bind at the transfer case.
Retaining the ABS required ingenuity. Dynatrac turned the rear of the hub and pressed a tone ring into place behind the flange. The tone ring is "inside" the rotor. Then they welded a bracket and mounted a pickup to the spindle flange behind the hub. This was precision work in a tight space. The pickup and tone ring have much better protection from mud than they had with the original axle.
|The OEM calipers are dwarfed by the optional HD calipers used by Dynatrac.|
How my project progressed:
July 28, 1998 - Axle ordered.
September 11, 1998 - Dana parts for ABS sensor mount still on BO. Other parts ready for assembly.
September 23, 1998 - All parts arrived at Dynatrac, construction estimated to take two weeks.
October 9, 1998 - Axle is shipped from California by truck.
October 16, 1998 - It's Here!
|Axle arrives in a big crate that Sue says appears to be a coffin (mine?). Initial impression is: COWABUNGA! This is a heavy duty axle. Fit and finish appear flawless.|
October 20, 1998
- Installation process begins and hits a few small problems.
Details and photos of the installation
October 29, 1998 - Last bolt is tightened, the hubs are locked, and the axle is successfully tested.
The ARB air line is connected to the differential, but the air supply is not available until the utility bed is installed in a few weeks.
Communicating with the company via long distance to have a custom axle built has been frustrating. Every time I talked to the folks at Dynatrac, I had the feeling that all previous conversations had been forgotten, and we had to start over from scratch. There seemed to be one person there who knew what was happening, and if he was gone or busy, little useful communication occurred. Repeatedly I requested a "build sheet" with part numbers so I could repair the components when they broke or wore out. Each time we went through something like this:
so now I have the axle and no build sheet or part numbers came with it.
It uses 1 ton Ford hubs (because I know what Ford hubs look like, not because
Dynatrac told me!) which are made for a Ford wheel with a 0.100" larger
center hole. The Ram wheels will not fit over the small step in the hub
flange. I thought I had warned Dynatrac about that, but apparently I didn't
get it communicated (sigh, long distance is just not the same as being there).
The hubs had to come off to have the step turned down. Then I found that my F250 hub nut wrench would not fit the hub nut (good thing I HAD to take them off!, discovering this on a trail would not be fun!). A call to Dynatrac got SOME info from them about the appropriate wrench, after I convinced them that the hub had to come off because I had 9 Ram wheels with tires mounted and did not want to buy new wheels just so they would fit on the hub.
My fault: The 2" taller springs were a real bear to reinstall. I had forgotten that the first time we put the passenger side (long tube side) in first and then the driver's side second. Sue I wrestled the driver side spring into the tower and then moved to the other side. OOPS, BIG MISTAKE! With the jack under the carrier, the lighter long tube side did not have enough leverage to overcome the spring installed on the other side. To shorten the spring we were trying to install, I cautiously used the high-lift jack to compress the spring about 1.5", and chained the spring one coil from each end on two sides. We set a jack under the knuckle on the driver side and used it to lever the drivers side of the axle upward, pivoting the other side down. Then we wrestled the spring into place. Once the spring was seated, was easy to jack the axle enough to squeeze the spring and remove the chain.
I had a surprise Sunday when I tried to switch the brake lines from the original caliper to the new Ford style calipers. The Dodge hose to caliper bolt uses a coarse thread, the Ford caliper uses a fine thread. The only parts house open Sunday afternoon did not have the proper bolt. On Monday, a three hour tour of parts houses, Ford dealers, and salvage yards finally tuned up plenty at D&M Auto Parts' salvage yard ("sure, take a wrench and pull some off the calipers up there" - I started at the wrong end of the county!) Everyone else spent 20 minutes or more pecking at computer terminals looking for the part number and then pronouncing "no, we don't have any". FWIW: The 3/8X24 banjo bolt has been used on just about every Ford vehicle ever built with disk brakes! Most parts suppliers now rely on computers to tell them a part number, and they can't provide anything if the computer does not spit back a number. GRRR!
I ordered the axle with a yoke for a Spicer 1350 U-joint which is much larger and stronger than the Dodge 7290. Roanoke Auto Spring did not have a Spicer end for the OEM axle because it used different splines. The axle was cut, new splines were installed, and a Spicer end finished the job. The new sliding joint has a zerk fitting.
This axle was not inexpensive! - It was built by one of the best ( IMO ) in the business, and I am still trying to get enough information to know what I need for spare parts. There is more info in a $2 magazine article that I had archived several years ago than I have been able to get for an axle I paid $$$$ for. With the help of a Ford service manual and some magazine articles I have figured out just about all of the parts myself and will call Dynatrac one of these days to get the sources for few remaining mystery parts.
Many are asking about how to get manual hubs on the OEM axle:
News Flash: Great
news for Ram owners who want manual hubs.
See the October 2000 issue of Peterson's 4Wheel & Off-Road for "Axle Disconnect Delete". Dynatrac has developed a manual hub kit for the Dana 30 and 60 axles used in Jeep and Ram products. If enough interest is generated for a Dana 44 version, Dynatrac says if will be developed. A stage one kit replaces the original 30 spline axle with a 30 spline one piece version, and adds spindles and manual hubs. A stage 3 kit is available with 35 spline axles, 1480 cross joints, spindles, and of course - manual hubs. These kits do not provide a reverse cut ring and pinion, or strengthen the passenger side axle tube, or retain the 4wheel ABS. However, while not inexpensive, this kit would would cost considerably less than an entire axle assembly and it would be much easier to install.
For the DIY type with access
to a good axle shop:
You would need to get everything from the axle tube outward including the ball joints, knuckles, rotors, calipers, hubs, knuckle flange, and outer axle stubs. The Ford knuckle is sized differently than the Dodge, so the knuckle flanges will have to be transplanted to the Dodge axle (cut both flanges from the axle tubes, weld the Ford version onto the Dodge axle tube). There is no seal at the passenger side of the diff case, so the replacement axle will need a sealing surface at the CAD seal. I haven't checked into the feasibility of this because (frankly) my front end project is finished and I don't have time to spend chasing parts and details for other options. Here are some other considerations if you pursue the knuckle swap:
ARB Air Locker
The ultimate differential. On-road it acts like a stock differential. Off road you can lock the differential solid, so each axle must turn at the same speed, giving you incredible traction.
Normal operating pressure: 80 to 105 psi engaged. Operating Notes
Last update August 28, 2000