Launching in OD?
11-26-2007, 01:19 PM
#1
TECH Regular
Thread Starter
Join Date: Aug 2004
Location: Tyler, TX.
Posts: 443
Likes: 0
Received 0 Likes
on
0 Posts
Launching in OD? I just recently tore up my tranny and lost all forward gears coming out of the hole at the track. We are assuming its the rear sprag that let go and I was told that i should of been launching in D instead of OD and the sprag wouldn't of broke. Is this correct?
11-26-2007, 02:15 PM
#4
Well there is not much you can do to keep a sprag from failing. It can only take so much energy. The input sprag is brought on when "D" is selected. It will help support the input assembly when digging. The rear or Low Sprag is on anytime it sees 1st gear.
It might be that the input drum failed... did it have reverse after it broke? I can't remember what you said in the last post regarding this unit.
g
It might be that the input drum failed... did it have reverse after it broke? I can't remember what you said in the last post regarding this unit.
g
11-26-2007, 02:56 PM
#6
12 Second Club
Join Date: Oct 2007
Location: Ellensburg WA
Posts: 40
Likes: 0
Received 0 Likes
on
0 Posts
From what you've said above the rear or low sprag will be engaged no matter what position the shifter is in as long as the transmission itself is in 1st gear (i.e. at a stop). Therefore, the only differentiation at a stop, as far as sprags go, would be selecting OD (not having the input sprag on, having low sprag on), or selecting D,2,1 (having the input sprag on, having low sprag on)...
Is this correct?
If so, then selecting D would indeed add a level of stability to the tranny not seen in OD...preventing failure in certain circumstances where it otherwise would occur if OD would have been selected...
...or is the difference simply negligible?
11-26-2007, 03:19 PM
#7
Well the interesting thing is... in manual low, park and reverse the low clutch pack is applied... maybe that is what your builder was trying to say. Maybe not.
Yes that is correct.
I don't think we can say that by choosing any gear we will prevent a failure, but there are advantages to leaving in "D" as we have discussed.
g
Yes that is correct.
I don't think we can say that by choosing any gear we will prevent a failure, but there are advantages to leaving in "D" as we have discussed.
g
Trending Topics
11-26-2007, 03:25 PM
#8
TECH Regular
Thread Starter
Join Date: Aug 2004
Location: Tyler, TX.
Posts: 443
Likes: 0
Received 0 Likes
on
0 Posts
So your saying that this could of led to the failure of the rear sprag by having it in OD instead of D? If so why does everybody say to leave it in OD for better launches and 2-3 shifts?
11-26-2007, 04:00 PM
#9
Are you certain that the rear sprag has failed? Probably is but are you sure by now? It could be that you are simply putting too much H/P to the ground. What kind of power are you making?
Can you point out some of the posts where folks have recommended launching in OD? I think what they are trying to say it instead of trying to manually shift the tranny, put in OD and run it.
I myself have always advocated placing it in D.
g
11-26-2007, 04:22 PM
#10
TECH Regular
Thread Starter
Join Date: Aug 2004
Location: Tyler, TX.
Posts: 443
Likes: 0
Received 0 Likes
on
0 Posts
No I'm not saying that launching in OD could have caused the Low Roller / Rear Sprag to fail. My point is, by placing the tranny in D the input sprag is applied and it adds strength to the input assy, generally speaking.
Are you certain that the rear sprag has failed? Probably is but are you sure by now? It could be that you are simply putting too much H/P to the ground. What kind of power are you making?
Can you point out some of the posts where folks have recommended launching in OD? I think what they are trying to say it instead of trying to manually shift the tranny, put in OD and run it.
I myself have always advocated placing it in D.
g
Are you certain that the rear sprag has failed? Probably is but are you sure by now? It could be that you are simply putting too much H/P to the ground. What kind of power are you making?
Can you point out some of the posts where folks have recommended launching in OD? I think what they are trying to say it instead of trying to manually shift the tranny, put in OD and run it.
I myself have always advocated placing it in D.
g
11-29-2007, 11:55 AM
#12
TECH Regular
Thread Starter
Join Date: Aug 2004
Location: Tyler, TX.
Posts: 443
Likes: 0
Received 0 Likes
on
0 Posts
Well they got the transmission out and apart and the sprags were in great shape. Somehow i cracked and stripped the planetarys(sp). 
They were supposed to be top of the line too. So i have no idea what to do now!
They were supposed to be top of the line too. So i have no idea what to do now! 
11-29-2007, 12:48 PM
#14
TECH Regular
Thread Starter
Join Date: Aug 2004
Location: Tyler, TX.
Posts: 443
Likes: 0
Received 0 Likes
on
0 Posts
I think he said something about a 6 pinion maybe. Dont know the brand and it let go on the launch.
11-29-2007, 01:04 PM
#16
TECH Regular
Thread Starter
Join Date: Aug 2004
Location: Tyler, TX.
Posts: 443
Likes: 0
Received 0 Likes
on
0 Posts
I doubt there are any then and just heard him wrong. lol As u can tell i have no clue what so ever when it comes to a transmission and thats why i ask questions. I've planned on getting some pics snapped of the broken planet to post up here for review.
11-29-2007, 01:15 PM
#17
The aftermarket planetary gear sets are made of inferior steel and are prone to failing. That is why you see all of the Sponsors running the OEM parts. It definately is a situation whereby you get what you pay for.
Glad you have it under control!
g
Glad you have it under control!
g
11-29-2007, 01:36 PM
#18
We look forward to seeing the pictures. I mean it is possible they are oem and you just got a bad one, Or its possible you have more torque and the ability to put it to the ground than they can handle. .I doubt it, but its possible not knowing more about you car and what kinda times it runs etc, But I would bet on a bad or inferior parts, Again look forward to seeing the pics. Though I have seen this before its not a common occurance. Or at least it hasnt been for me. But its good to note as was mentioned and ill add that the Builder is at least 50 percent of the equation but the parts I would say are the other 50 percent if they are not up to par it makes no difference how good the builder is.
Good luck with it. And if it helps with that type failure it would not matter what gear position you had it in when it broke.
__________________
11-29-2007, 03:18 PM
#19
TECH Regular
Thread Starter
Join Date: Aug 2004
Location: Tyler, TX.
Posts: 443
Likes: 0
Received 0 Likes
on
0 Posts
We look forward to seeing the pictures. I mean it is possible they are oem and you just got a bad one, Or its possible you have more torque and the ability to put it to the ground than they can handle. .I doubt it, but its possible not knowing more about you car and what kinda times it runs etc, But I would bet on a bad or inferior parts, Again look forward to seeing the pics. Though I have seen this before its not a common occurance. Or at least it hasnt been for me. But its good to note as was mentioned and ill add that the Builder is at least 50 percent of the equation but the parts I would say are the other 50 percent if they are not up to par it makes no difference how good the builder is.
Good luck with it. And if it helps with that type failure it would not matter what gear position you had it in when it broke.
Good luck with it. And if it helps with that type failure it would not matter what gear position you had it in when it broke.
