opinions on radius arms for dana 44

[mazdamama]

im doing an sas on a budget and have found everything i need for a good price except for radius arms for a hp dana 44. would it be worth it to make some homemade extended arms or should i just save up and buy some duffs, or cage arms first? any advice would be greatly appreciated. maybe some pics of custom arms and frame mounts.

 

[JohnnyU]

Bray's build is a great example of extending Ford radius arms.

I can also personally attest to the fact that his truck works great.


http://therangerstation.com/forums/showthread.php?t=12686&highlight=daily+doubler

 

[Bray D]

Thanks for the plug John haha. End of page 19 is a good start for the RA build.

If you have the cast wedges and are set on doing the RA setup, then by all means, extend em with flex joints and be done.

Having gone that route, I wish I would've gotten a housing without cast wedges and built a 3 link like JohnnyU did. Its essentially a radius arm setup, but it eliminates the bind that is unavoidable with traditional radius arms. Also, you have the freedom to mount the arms wherever you want, and set the caster to whatever you want. Without a way to bend my RA material (2"x.250" DOM) I was limited with where I could mount the arms at the frame due to the caster angle.

BUT, like JohnnyU said, it definitely works. I don't plan to change it anytime soon anyways.

 

[mazdamama]

thanks, thats just what i was looking for, mine will be a little further out on the frame though cause im keeping them full widths. i just read over your entire thread, your work is really nice and your truck is awesome. does handle well at highway speeds? do the tires rub on the RA at all?

 

[Bray D]

Thanks. My arms are tucked inside the frame. At the same location, I would expect your arms to be under the frame, being full-width.

Handles great on the road. Straight on short bumps may be a little more harsh than the TTB, and it sways a bit more in the turns (no anti-sway bar). Other than that its very predictable, and has arguably no bump steer. WAY better steering than the TTB had anyways.

On flat ground I can turn lock to lock without rubbing the arms. There is bare spots on the arms where it has rubbed though. That may be from an obstacle pushing my tire into the arm while they're at low pressure. The tires measure 34.5" - damn near true 35's.

 

[JohnnyU]

Thanks for the plug John haha. End of page 19 is a good start for the RA build.

I call things how I see 'em!

Having gone that route, I wish I would've gotten a housing without cast wedges and built a 3 link like JohnnyU did. Its essentially a radius arm setup, but it eliminates the bind that is unavoidable with traditional radius arms. Also, you have the freedom to mount the arms wherever you want, and set the caster to whatever you want. Without a way to bend my RA material (2"x.250" DOM) I was limited with where I could mount the arms at the frame due to the caster angle.

BUT, like JohnnyU said, it definitely works. I don't plan to change it anytime soon anyways.

I am pretty happy with my mine turned out, it flexes fairly well for what it is. I'm going to do some playing around with the spring buckets this winter and figure out what length of limiting straps I really need, and get them mounted up. I've thought about modifying mine to be a "true" 3-link, but I just dont see the gains as being enough to mess with it.

 

[mazdamama]

Thanks. My arms are tucked inside the frame. At the same location, I would expect your arms to be under the frame, being full-width. .

thanks for the info, how come i would want the radius arms mounted inside the frame, for full width axles as well?

also, ive got 5,38 gears, and right now i have 35 inch tires, would this gear ratio be better for 37's and with chromolly axle shafts could it handle 37's?
why do people build doublers, when they could just put really low gears in the axles? does it take some stress off the drivetrain? or does it just give you better options for what speed you want to drive at? i appoligize, i know i am asking a lot of questions.

 

[JohnnyU]

thanks for the info, how come i would want the radius arms mounted inside the frame, for full width axles as well?

also, ive got 5,38 gears, and right now i have 35 inch tires, would this gear ratio be better for 37's and with chromolly axle shafts could it handle 37's?
why do people build doublers, when they could just put really low gears in the axles? does it take some stress off the drivetrain? or does it just give you better options for what speed you want to drive at? i appoligize, i know i am asking a lot of questions.

From a component longevity perspective, it's best to maintain driveshafts and u-joints as high-speed/low torque. This would mean that the majority of your gear reduction should take place in the axles, or wheelhubs (such as hub planetary reduction in ZF axles or the drop boxes found on Unimog axles). This is either impractical or impossible on most common axles, so therefore in an effort to maintain some pinion strength by not going to such a deep gear, a doubler is used to give the additional gear reduction.

Doublers also give multiple speed and reduction options (High/high, High/low, and Low/Low) Other transfercases, such as a Dana 300 or NP205, would give you the option of having only front wheels powered, only rear wheels powered, or both.

As for the Ford radius arms, you're somewhat limited to their placement due to the bushing design, but if they need to be built outside the frame, you want to be sur that there is no suspension binding, and that your tires will clear. The linked-style radius arm suspension allows a bit more freedom with link geometry. I was able to design mine based a bit more off of a 'true' 3-link which helped both with tire clearance, and suspension movement.

 

[Bray D]

Again, JU hits the nail on the head.

For me to have the same reduction I have with my doubler, I'd need 11.3:1 gears in my axles. This is just not practical. As JU said, I'd rather not go deeper than 5.13 in the axles, due to pinion strength (pinion gets smaller as the ratio gets higher). Doublers offer awesome gearing selection. I have the "stock" 2.48:1 t-case ratio for trail running, then in double low I have 6.15:1 for crawling. I also have a manual transmission so I have gears 1-5 for choosing the optimum gearing for any type of terrain.

I think 5.13's would be perfect for 35's, and 5.38's may be a bit deep for 35's (better for the 37's) as far as highway driving is concerned. I have 4.56's with 35's and my speedo is dead on, but my truck is still a turd due to the added rotating mass. 5.13's will make your speedo read a bit faster than what you're going, but would compensate power-wise for the added rotating mass.

For the most part, you're stuck mounting the radius arms wherever they end up at the frame (whether thats under/inside/or outside the frame). Even though they have bushings at the axle end, they don't allow for a lot of movement after the caps have been torqued on. I squeezed mine in ~ 1" per side from the "natural" width at the frame end, and wish I hadn't. Though I have done it multiple times, its a bitch to get the arms back into the crossmember without loosening the caps at the axle end.

 

[mazdamama]

wow. thanks a lot, hopefully the gears i get with these axles are high quality, otherwise ill probably be braking things left and right with 37s and 5.58s.

 

[Bray D]

You may be alright. It depends on a lot of variables - mainly your driving style.