700R4/Atlas 4 speed update

[toddz69]

In my best terrible Gary Coleman imitation:

What choo talkin 'bout, Willis?

There was some talk on the B'fix mailing list about it the other day. Scott from Rockstomper broke one pretty spectacularly recently.

Todd Z.

 

[Mark]

There was some talk on the B'fix mailing list about it the other day. Scott from Rockstomper broke one pretty spectacularly recently.
Todd Z.

Oh that. I won't let one inconclusive incident sway me.
Hopefully, I won't be eating those words. %)

 

[toddz69]

Oh that. I won't let one inconclusive incident sway me.
Hopefully, I won't be eating those words. %)

Are you buying one?

Todd Z.

 

[Frankenhorse]

Any more progress/pics. Was thinking putting that 4sp behind my ZF.


Sub plot: What did he?/How did he break it?


Back to the install. That 700R4 is looking good.

 

[Mark]

Are you buying one?

Todd Z.

I'm about ready to pull the trigger.
I have serious rear-end issues.

 

[gddyap]

I have serious rear-end issues.

Taken out of context, that could sound funny.

 

[toddz69]

I'm about ready to pull the trigger.
I have serious rear-end issues.

Please elaborate! (on your truck's rear end issues, not yours ). Driveline angles? Driveshaft length? I need some more data points before I decide what to do as well.

Todd Z.

 

[toddz69]

Sub plot: What did he?/How did he break it?

Here are the issues I know of on Scott's Hi9 unit:

6 teeth broken off ring gear
cracks in pinion gear
tapered pinion journal wear
case distorted out of square

This is on a 3800 lb. comp rig with a 300hp 5.0, C6, Atlas, 5.13 gears and 39" Krawlers so it's far, far, far more abusive than what we put our trucks through. Interesting data point, but certainly not an apples to apples comparison.

Todd Z.

 

[toddz69]

Any more progress/pics. Was thinking putting that 4sp behind my ZF.

Back to the install. That 700R4 is looking good.

No more pics at this time (other than the trans with painted crossmember installed). I have some stud trimming to do on the t-case and some slight material removal/polishing to do on the 1" spacer between the tranny and the t-case. Between a 5-6 day vacation last weekend and deciding to go mt. biking instead of wrenching yesterday, I haven't had much time to work on it. If we get the case installed an evening this week, I'll post pics.

Todd Z.

 

[Mark]

Please elaborate! (on your truck's rear end issues, not yours ). Driveline angles? Driveshaft length? I need some more data points before I decide what to do as well.
Todd Z.

Nothing so glamorous. I currently have 28 spline axles, twisted one recently. Rear axle seal area on both sides of the housing is washed out (broken lip on one side) and I'm leaking gear fluid from both ends. The current rear end is the bastard son of 5 different housings with big bearing ends welded on.
Sooo... I want to replace the housing with a beefy Currie housing, and since I have to replace the center section to upgrade to 35 spline, might as well drop the extra few Ben Franklin's to get the Hi9.
That's my "logic" anyway. I'll be spending more on the rear end then all but one of the Bronco's I have purchased, but ... wow, it'll be a nice rear.

 

[Frankenhorse]

I like a good rear:-*

 

[truehi9]

Hi there.

Hopefully I can shed some light on Scott's breakage for everybody.

1. At an average comp event about 3 HP D60s break a ring and pinion. So, it is not uncommon to see a r&p break in a comp rig. I know this from the other comp teams running Hi9's that used to run HP D60s.

2. There is no loss in strength in our HP because of the load bolt. I know this because HP rear diffs usually break the tips of the teeth off when they deflect. In Scott's case 2 of the ring gear teeth were broke off about an 1/8 above the flat area of the ring gear and 2 teeth were broke off/ripped out about an 1/8 inch below that flat root area. This occurs from shock loading or landing on the rear tires with the weight of the vehicle and not lifting off the gas. In other words near max motor torque x low gear tranny ratio x low range t-case ratio spinning the tires and then stopping them with a 3800 pound rig shoving them into the ground. My shock loading analogy is try to push a nail into a board and then see how much easier it is to shock load (pound) that same nail in.

3. The taper wear on Scott's r&p is on the 3rd bearing. It was caused from the busted ring gear teeth pushing the spinning pinion into the 3rd bearing. You would not see this on a setup without a loadbolt because the ring gear would just deflect or get pushed away. Since the ring gear was against the load bolt the spinning pinion was pushed into the third bearing. Scott had the pinion out a month earlier for inspection while fixing a leak and there was no abnormal wear whatsoever.

4. Our 5.14's have about 37 percent less tooth material and contact area than our next closest gear ratio. They are only equal to the tooth size and overlap of a D60. Our 5.14's are probably still stronger since the pinion head is larger so they apply less pressure to the ring gear teeth than a D60 and there is no deflection on our unit.

5. Scott had his brother buy the parts for him through his brothers axle shop by telling us they wanted to assemble them there so they could make more money on the sale. The main topic of this conversation was buying the stuff cheaper not what the parts were actually going to be used for. Had we known the intentions for the Hi9s the 5.14s would not have been sold. We feel like we were deceived since we were told the parts were for a customer and not his brother. That deception has caused us a well publicized failure and Scott a broken diff.

6. The other comp teams running Hi9s went from cryoing and then changing D60 r&p's every 2 to 3 events to running our noncryoed stuff for a season and sending them in for inspection.

7. NOTHING is unbreakable.

 

[Mark]

I'm about ready to pull the trigger.
I have serious rear-end issues.

Trigger pulled.
I asked the gentleman at Hi9 about the incident and he elaborated basically what he posted.
I did not specifically mention this thread, just that I heard about the incident on the internet. I think his post should be posted on the Bfix mailing list also, just so there is some response to a "rumor".

 

[av8rds]

UPS dropped off my new 4sp yesterday, gee it purty ;@) guess I better get going to catch up to your install. Do you have any more pic's?

Considering the level of work required to take the rear axle out to cut and rotate the spring pads I'm seriously considering just 4-linking and shaving it while its out. Or maybe just buy a truehi9 and save some work, well kinda 6 of one 1/2 dozen of the other.

 

[toddz69]

UPS dropped off my new 4sp yesterday, gee it purty ;@) guess I better get going to catch up to your install. Do you have any more pic's?

Considering the level of work required to take the rear axle out to cut and rotate the spring pads I'm seriously considering just 4-linking and shaving it while its out. Or maybe just buy a truehi9 and save some work, well kinda 6 of one 1/2 dozen of the other.

I still haven't decided which route to take on mine either. Thanks to truehi9 for posting his responses to the info I posted earlier on the breakage.

You will probably surpass me quickly in your conversion process. I am still struggling getting my t-case to mate up correctly to the adapter on my trans. We get it to about 1/4-3/8" of seating and then we can't get it any closer. We're going to pull and try again tonight. Hopefully we will find the exact issue tonight that's holding it up.

Todd Z.

 

[av8rds]

have you thought about an additional rear support of the t-case? I didnt like the "L" leg(hung too low for my liking) on the advanced adapter from the 700 to the dana 20 so I cut it off and have been using the stock tranny mount since. Now I'm going to have 120+ lbs out there and I think I want more support. I did find a company that makes a rear support. I dont have it on my home computer but I believe it was by a company call roarkworks?

 

[toddz69]

have you thought about an additional rear support of the t-case? I didnt like the "L" leg(hung too low for my liking) on the advanced adapter from the 700 to the dana 20 so I cut it off and have been using the stock tranny mount since. Now I'm going to have 120+ lbs out there and I think I want more support. I did find a company that makes a rear support. I dont have it on my home computer but I believe it was by a company call roarkworks?

Not sure on that. I probably won't - at last for the time being. The Atlas 4 is only 15 lb. heavier than the standard Atlas but it is cantilevered out there a bit.

Todd Z.

 

[toddz69]

You will probably surpass me quickly in your conversion process. I am still struggling getting my t-case to mate up correctly to the adapter on my trans. We get it to about 1/4-3/8" of seating and then we can't get it any closer. We're going to pull and try again tonight. Hopefully we will find the exact issue tonight that's holding it up.

Todd Z.

Well, still no luck tonight either, but we found the problem. The output shaft on the 700 is bottoming in the input on the 4 speed Atlas before the two mate flush. So....I contacted Kincade and hopefully he will address it with AA asap. Looks like I need about 0.25" more adapter thickness to keep things from bottoming out.

Sigh.........

Todd Z.

 

[av8rds]

I know when I mated the 700 to the Dana I had the same problem and all it required was trimming a bit off the output shaft. I even think it was in the directions that I might have too. maybe same problem. I really didnt like the idea but there was no way around it and I havent had any problems with it.

 

[toddz69]

I know when I mated the 700 to the Dana I had the same problem and all it required was trimming a bit off the output shaft. I even think it was in the directions that I might have too. maybe same problem. I really didnt like the idea but there was no way around it and I havent had any problems with it.

That is one option I've considered. Had to do it, of course, years ago when I put the 435 in my truck. Don't want to do it if I don't have to, though.

I'll wait to see what AA says and go from there.

Todd Z.