I purchased and installed the EMS HC-00D-SRW-35 35 spline locking hub kit on my 05 2500. The information I have on the DynaTrac kit is word of mouth from another TDR member. Before I bought the kit I did some searches for the differences between the two, but there was not a lot of information on TDR. DynaTrac did not respond to my product inquiry via their site's email link. EMS did and they cost a lot less (or so I thought) so I went with them.
Turns out I didn't pay close enough attention to the DynaTrac website. I thought the $1895 kit was 30 spline and you'd have to pay even more for the “Stage II” upgrade to get 35 splines. I believe the standard $1895 DynaTrac kit for the 05 comes with 35 spline stub shafts. If DynaTrac gives a TDR discount, then the price difference really is not that much between the two kits. Is the cost savings is worth it? Maybe, if you're ready for some extra work beforehand. You'll have to decide for yourself.
As for the physical differences, EMS uses a five hole Ford spindle that gets re-drilled with the four bolt pattern for our trucks, hence the EMS logo covering the spindle bolt holes in all the EMS advertisement pictures. DynaTrac uses a custom spindle with four threaded holes. There must be something different about the stub shafts or spindles (or both) since the EMS kit moves the ujoint outboard of the stock location, away from the center of the truck, while the DynaTrac kit moves the ujoint slightly inboard. EMS says moving the ujoint outboard is to minimize ujoint bind while turning. It sounds like some of the DynaTrac kits come with the wheel studs and bearing races installed, some don't. The EMS kit came with them loose.
The member who installed a DynaTrac kit said everything fit as designed. I was not so lucky with the EMS kit. EMS customer service was good.
Issues I ran into during the install:
One spindle had been mis-drilled and required replacement.
Both spindles had bearing fitment issues which required polishing parts of the spindle.
Both ABS blocks required grinding due to interference with the hubs.
One stub shaft had minor indentations on the surface where the needle bearing rides. I just polished it up so I could finish the install.
One stub shaft required grinding the yokes to fit through the steering knuckle.
Both lockouts were loose and rattled. Added additional o-rings.
Lessons learned:
1. Inspect everything carefully prior to starting the install.
2. Dry fit everything together before doing the actual install! Its much easier to deal with issues before parts are bolted to the truck and covered in grease.
All in all the kit was more of a chore to install than I expected. Not really a big deal, just after fighting to get the unit bearings out I was expecting a simple bolt on for the kit. I'm not so sure about moving the ujoint from the stock location, both from the ujoint bind standpoint and because of where the internal axle shaft seal at the differential rides on the shaft. I am also somewhat concerned that the spindles fit into the steering knuckles loosely. All the other spindles I've worked on, Dana 60, GM 10 bolt and Jeeps, had all fit tightly in the knuckle. Maybe once all the rust from the unit bearings was removed, the hole in the knuckle was slightly oversized? So far everything works.
Feel free to post up your install issues, good or bad, with either kit. Hopefully this thread will help others to make a more informed purchase.
PS if anybody has the DynaTrac kit and hasn't installed it yet, please measure the spindle OD where it fits into the steering knuckle. I'll be pulling mine to do ball joints soon and will measure it to see if there is any size difference compared to the DynaTrac spindle.
Turns out I didn't pay close enough attention to the DynaTrac website. I thought the $1895 kit was 30 spline and you'd have to pay even more for the “Stage II” upgrade to get 35 splines. I believe the standard $1895 DynaTrac kit for the 05 comes with 35 spline stub shafts. If DynaTrac gives a TDR discount, then the price difference really is not that much between the two kits. Is the cost savings is worth it? Maybe, if you're ready for some extra work beforehand. You'll have to decide for yourself.
As for the physical differences, EMS uses a five hole Ford spindle that gets re-drilled with the four bolt pattern for our trucks, hence the EMS logo covering the spindle bolt holes in all the EMS advertisement pictures. DynaTrac uses a custom spindle with four threaded holes. There must be something different about the stub shafts or spindles (or both) since the EMS kit moves the ujoint outboard of the stock location, away from the center of the truck, while the DynaTrac kit moves the ujoint slightly inboard. EMS says moving the ujoint outboard is to minimize ujoint bind while turning. It sounds like some of the DynaTrac kits come with the wheel studs and bearing races installed, some don't. The EMS kit came with them loose.
The member who installed a DynaTrac kit said everything fit as designed. I was not so lucky with the EMS kit. EMS customer service was good.
Issues I ran into during the install:
One spindle had been mis-drilled and required replacement.
Both spindles had bearing fitment issues which required polishing parts of the spindle.
Both ABS blocks required grinding due to interference with the hubs.
One stub shaft had minor indentations on the surface where the needle bearing rides. I just polished it up so I could finish the install.
One stub shaft required grinding the yokes to fit through the steering knuckle.
Both lockouts were loose and rattled. Added additional o-rings.
Lessons learned:
1. Inspect everything carefully prior to starting the install.
2. Dry fit everything together before doing the actual install! Its much easier to deal with issues before parts are bolted to the truck and covered in grease.
All in all the kit was more of a chore to install than I expected. Not really a big deal, just after fighting to get the unit bearings out I was expecting a simple bolt on for the kit. I'm not so sure about moving the ujoint from the stock location, both from the ujoint bind standpoint and because of where the internal axle shaft seal at the differential rides on the shaft. I am also somewhat concerned that the spindles fit into the steering knuckles loosely. All the other spindles I've worked on, Dana 60, GM 10 bolt and Jeeps, had all fit tightly in the knuckle. Maybe once all the rust from the unit bearings was removed, the hole in the knuckle was slightly oversized? So far everything works.
Feel free to post up your install issues, good or bad, with either kit. Hopefully this thread will help others to make a more informed purchase.
PS if anybody has the DynaTrac kit and hasn't installed it yet, please measure the spindle OD where it fits into the steering knuckle. I'll be pulling mine to do ball joints soon and will measure it to see if there is any size difference compared to the DynaTrac spindle.
Last edited: