Why won't my 4'spd go into 2'nd under high rpm? - Moparts Forums

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Why won't my 4'spd go into 2'nd under high rpm? #842427 10/30/10 11:00 PM 10/30/10 11:00 PM
Joined: Jun 2004 Posts: 1,496 Sask, Can. 7 72demon416 OP pro stock
72demon416 OP pro stock 7 Joined: Jun 2004 Posts: 1,496 Sask, Can.	My trans will shift into 2'nd...ok... under normal driving but when the revs are up it will completely block you out of the gate until the revs drop again. 2 years ago when I grenaded my last engine I was making some passes and missed a powershift into 2'nd on one of my last runs- I'm assuming I damaged something. It use to shift perfect under high rpm... Or could it be something as simple as pressure on the input shaft from the bell not being dialled in (I'm guessing not likely )

Re: Why won't my 4'spd go into 2'nd under high rpm? [Re: 72demon416] #842428 10/30/10 11:12 PM 10/30/10 11:12 PM
Joined: Jan 2003 Posts: 2,734 Charlotte, NC 4 446acuda master
446acuda master 4 Joined: Jan 2003 Posts: 2,734 Charlotte, NC	If pilot hole and face runout are in specs the next thing to check is the clutch air gap. With the pedal pushed to the floor you should be able to get a .040"-".050 feeler gauge between the flywheel and the disc. If you don't have enough air gap you won't get a clean power shift.

Re: Why won't my 4'spd go into 2'nd under high rpm? [Re: 446acuda] #842429 10/30/10 11:49 PM 10/30/10 11:49 PM
Joined: Jun 2004 Posts: 1,496 Sask, Can. 7 72demon416 OP pro stock
72demon416 OP pro stock 7 Joined: Jun 2004 Posts: 1,496 Sask, Can.	At this point a granny shift is not even possible under high rpm. I adjusted the clutch tonight with absolutely no difference... I'm assuming that if it was a clutch problem there would be a problem with 3'rd as well?

Re: Why won't my 4'spd go into 2'nd under high rpm? [Re: 72demon416] #842430 10/30/10 11:58 PM 10/30/10 11:58 PM
Joined: Jan 2003 Posts: 32,932 Grand Prairie,Texas stumpy I Win
stumpy I Win Joined: Jan 2003 Posts: 32,932 Grand Prairie,Texas	Bad brass syncros in the trans.

Re: Why won't my 4'spd go into 2'nd under high rpm? [Re: stumpy] #842431 10/31/10 12:51 AM 10/31/10 12:51 AM
Joined: Oct 2006 Posts: 3,054 USA B b54406barrel master
b54406barrel master B Joined: Oct 2006 Posts: 3,054 USA	Quote: Bad brass syncros in the trans. If it only happens on second gear. Or maybe a bad 1-2 slider. I use to replace those a lot on Muncies when they wouldn't shift into 2nd under power.

Re: Why won't my 4'spd go into 2'nd under high rpm? [Re: b54406barrel] #842432 10/31/10 01:07 AM 10/31/10 01:07 AM
A Anonymous Unregistered
Anonymous Unregistered A	I have encountered the exact same problem with my 833 4 speed in my dart using a centerforce dual friction....its caused by the pressure plate not releasing because of the centrifugal force....i went to a Mcleod soft lock clutch problem solved...amazing clutch...completely adjustable for your application...highly recommended

Re: Why won't my 4'spd go into 2'nd under high rpm? [Re: b54406barrel] #842433 10/31/10 01:35 AM 10/31/10 01:35 AM
Joined: Aug 2003 Posts: 12,291 Kent, Wa 340SHORTY Truck Nut
340SHORTY Truck Nut Joined: Aug 2003 Posts: 12,291 Kent, Wa	Quote: Quote: Bad brass syncros in the trans. If it only happens on second gear. Or maybe a bad 1-2 slider. I use to replace those a lot on Muncies when they wouldn't shift into 2nd under power. I am truckless..

Re: Why won't my 4'spd go into 2'nd under high rpm? #842434 10/31/10 01:41 AM 10/31/10 01:41 AM
Joined: Jun 2004 Posts: 1,496 Sask, Can. 7 72demon416 OP pro stock
72demon416 OP pro stock 7 Joined: Jun 2004 Posts: 1,496 Sask, Can.	My setup hasn't changed and I've been using the same McLeod clutch setup for 5 years- which shifted into 2'nd just fine prior to my missed shift. I'm leaning towards damaged syncro/slider problems.

Re: Why won't my 4'spd go into 2'nd under high rpm? [Re: 72demon416] #842435 10/31/10 05:24 PM 10/31/10 05:24 PM
Joined: Jan 2003 Posts: 1,436 Oklahoma City OK Cudajon pro stock
Cudajon pro stock Joined: Jan 2003 Posts: 1,436 Oklahoma City OK	The 833 is notorious for polishing the synchros. I used to keep a spare tranny available with new synchros when I was racing the 4 speed. (Polished synchros will not grab and so you cannot get the slider to engage) Drives around at normal speeds ok, but will not power shift. http://www.youtube.com/watch?v=4J3K94cRC1c

Re: Why won't my 4'spd go into 2'nd under high rpm? [Re: Cudajon] #842436 10/31/10 07:12 PM 10/31/10 07:12 PM
Joined: Apr 2010 Posts: 398 Texas 7 70Runnerdude enthusiast
70Runnerdude enthusiast 7 Joined: Apr 2010 Posts: 398 Texas	Is this the same reason why a friends tranny would pop out of 2nd on deceleration ?

Re: Why won't my 4'spd go into 2'nd under high rpm? #842437 10/31/10 07:51 PM 10/31/10 07:51 PM
Joined: Oct 2003 Posts: 4,013 South Park, Pa. 68LAR master
68LAR master Joined: Oct 2003 Posts: 4,013 South Park, Pa.	Quote: ....using a centerforce dual friction....its caused by the pressure plate not releasing because of the centrifugal force.... not a chance of this being true. Most likely a slider, brass ring or the second gear dog teeth or maybe all three. 4 speed street legal. Best time 10.99 @ 124 mph on 93 octane pump gas @ 3926# total weight

Re: Why won't my 4'spd go into 2'nd under high rpm? [Re: 70Runnerdude] #842438 10/31/10 08:20 PM 10/31/10 08:20 PM
Joined: Jan 2003 Posts: 1,436 Oklahoma City OK Cudajon pro stock
Cudajon pro stock Joined: Jan 2003 Posts: 1,436 Oklahoma City OK	70 Runner your friends problem is probably due to linkage adjustment and its not fully engaging 2nd gear. Although bent/missing teeth on the slider or synchro could cause it. http://www.youtube.com/watch?v=4J3K94cRC1c

Re: Why won't my 4'spd go into 2'nd under high rpm? [Re: 68LAR] #842439 10/31/10 08:22 PM 10/31/10 08:22 PM
Joined: Jan 2003 Posts: 1,436 Oklahoma City OK Cudajon pro stock
Cudajon pro stock Joined: Jan 2003 Posts: 1,436 Oklahoma City OK	68LAR I totally agree with you. Centerforce doesn't have that problem. http://www.youtube.com/watch?v=4J3K94cRC1c

Re: Why won't my 4'spd go into 2'nd under high rpm? [Re: Cudajon] #842440 10/31/10 08:53 PM 10/31/10 08:53 PM
Joined: Sep 2003 Posts: 1,688 Marlboro, NY, USA R Rick_Ehrenberg top fuel
Rick_Ehrenberg top fuel R Joined: Sep 2003 Posts: 1,688 Marlboro, NY, USA	Quote: 70 Runner your friends problem is probably due to linkage adjustment and its not fully engaging 2nd gear. Although bent/missing teeth on the slider or synchro could cause it. Worn dog teeth on the speed gear usually cause this. Rick

Re: Why won't my 4'spd go into 2'nd under high rpm? #842441 10/31/10 09:43 PM 10/31/10 09:43 PM
Joined: Mar 2006 Posts: 9,839 MI, usa dvw master
dvw master Joined: Mar 2006 Posts: 9,839 MI, usa	Quote: I have encountered the exact same problem with my 833 4 speed in my dart using a centerforce dual friction....its caused by the pressure plate not releasing because of the centrifugal force....i went to a Mcleod soft lock clutch problem solved...amazing clutch...completely adjustable for your application...highly recommended My Challenger has a Centerforce. It is with out a doubt the best clutch I have ever used. Many full throttle 12 second passes. I've never even had to adjust it. Doug

Re: Why won't my 4'spd go into 2'nd under high rpm? [Re: Rick_Ehrenberg] #842442 10/31/10 10:01 PM 10/31/10 10:01 PM
Joined: Jun 2004 Posts: 1,496 Sask, Can. 7 72demon416 OP pro stock
72demon416 OP pro stock 7 Joined: Jun 2004 Posts: 1,496 Sask, Can.	Well it appears the general consensus is that it will have to come out for repairs so it looks like it's time to upgrade to the 18 spline while it's out. Thanks guys!

Re: Why won't my 4'spd go into 2'nd under high rpm? #842443 10/31/10 10:26 PM 10/31/10 10:26 PM
Joined: Jan 2003 Posts: 8,089 Sorrento, BC, Canada 4speeds4me master
4speeds4me master Joined: Jan 2003 Posts: 8,089 Sorrento, BC, Canada	Quote: I have encountered the exact same problem with my 833 4 speed in my dart using a centerforce dual friction....its caused by the pressure plate not releasing because of the centrifugal force....i went to a Mcleod soft lock clutch problem solved...amazing clutch...completely adjustable for your application...highly recommended The problem often encountered with a diaphragm clutch and high RPM shifts are the clutch pedal not returning due to being unable to overcome the overcenter spring. NEVER have I seen the problem you are describing with the diaphragm or any other clutch. 2 Demons...no, not my kids!

Re: Why won't my 4'spd go into 2'nd under high rpm? [Re: 4speeds4me] #842444 11/01/10 09:07 AM 11/01/10 09:07 AM
Joined: Jan 2003 Posts: 3,103 Phila Pa S scatpacktom master
scatpacktom master S Joined: Jan 2003 Posts: 3,103 Phila Pa	One more thing to consider is to make sure the REVERSE DETENT BALL isn't rolling around in the bottom of the case. They can sometimes pop out and then it is like pulling the shifter into a wall while going for second at high rpm.

Re: Why won't my 4'spd go into 2'nd under high rpm? [Re: scatpacktom] #842445 11/01/10 09:42 AM 11/01/10 09:42 AM
Joined: Jan 2006 Posts: 587 IL . usa C cjs69mope mopar
cjs69mope mopar C Joined: Jan 2006 Posts: 587 IL . usa	Just tip i used to repair many Japanese car transmissions for polished syncros and a good fix was to use some valve lapping compound and the old syncro/baulk ring to rough up the gear face before putting the new brass balking rings in . That was a T.S.B To hand rough the surface before installing new brass rings. Works great,also 75/140 synthetic lube helps for faster shifts than the thick 80/90 weight. The thinner the fluid the easier for the balk ring to "grab on" anyway good luck man, post up what u find. CJ 6279123-DSC_015037.jpg (122 downloads) 1969 Dodge Charger 1969 Dodge Superbee

Re: Why won't my 4'spd go into 2'nd under high rpm? [Re: 72demon416] #842446 11/01/10 10:06 AM 11/01/10 10:06 AM
Joined: Jan 2003 Posts: 8,940 Holly/MI D Dean_Kuzluzski master
Dean_Kuzluzski master D Joined: Jan 2003 Posts: 8,940 Holly/MI	I used to have the same problem until I added a solid steel motor mount on the LH side. The factory insulator let the motor torque up too much and bind the shift rods. Check out the above first before going internal to the trans. If you were getting a "gear clash" into 2nd when power shifting......then I'd jump to the blocking ring/synchro ailment. R.I.P.- Gary "Coop" Davis 02/09/68-05/13/04

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