Author Topic: Trans Shifting Issue  (Read 1156 times)

dannystarr

  • Hero Member
  • *****
  • Posts: 1347
    • View Profile
Trans Shifting Issue
« on: May 27, 2018, 09:39:05 PM »
Decided to change trans fluid and put in "Amsoil Synthetic Manual Transmission & Transaxle Gear Lube"  SAE 75W-90  API GL-4.
Seem to work ok for a while then after a couple hundred miles it starts acting weird. Let me try to explain this correctly. Trans is Muncie M21.

 SO, with the car warmed up, push in the clutch and it won't go in to first without EXCESSIVE pressure. Push like hell two or three times and it goes. This happens for 2nd gear also...Then out driving when you come up to a stop sign and begin downshifting, it falls in to 3rd, 2nd, and even 1st like butter! But ONLY if the car is moving!! Once you come to a complete stop, and it's a 6 way signal so ya throw it in neutral for the wait.. light turns green, push the clutch in, won't go in to 1st. However if the car is rolling even ONE mile an hour while down shifting, it drops right in to first gear. Now, once you GET it in to 1st while keeping the clutch depressed, it goes in and out no problem. Throw it back in neutral and let the clutch out, push it back in, won't go in to first. Read this twice before ya reply... ha ha  Linkage and clutch adjusted perfectly. If it wasn't it would bind all the time? Could it be the synthetic oil? Would like opinions before I change it out.  Danny

z28z11

  • Hero Member
  • *****
  • Posts: 1215
    • View Profile
Re: Trans Shifting Issue
« Reply #1 on: May 27, 2018, 09:59:42 PM »
Sounds almost like the three drive dogs on the synchro sleeve are worn, or out. Give us the rest of the story - how old is the trans, ever been freshened, have you tried selecting second or third before you try to select first (from a standstill). If the other synchros are good, then it points to the sleeve for first, obviously. Brass sleeve could be heavily worn, also, causing not enough friction to be able to slow the rotating gear mass down enough to select the gear. 

Before you start ripping things apart, drain the synthetic fluid out and go back to the recommended weight of conventional oil - worth a shot. What's the old saying, the simplest solution is the best solution ?

JMO,
Steve
1968 Z28 M21/U17 BRG/W
1969 Z28 X77/M20/VE3 LeMans/W
1969 L78 X66/N66 Cortez/BVT
1969 Z11 L48/M35/C60/C06

L78racer

  • Member
  • ***
  • Posts: 64
    • View Profile
Re: Trans Shifting Issue
« Reply #2 on: May 27, 2018, 10:34:58 PM »
you should be running GL-4 Gear Lube in a Muncie.

Paul

dannystarr

  • Hero Member
  • *****
  • Posts: 1347
    • View Profile
Re: Trans Shifting Issue
« Reply #3 on: May 27, 2018, 11:14:02 PM »
First line states...This happens for 2nd gear also... So yes, it does happen for second also. Just won't go in without a lot of effort. Trans has 55,000 Original miles and looks pretty good inside. I put in a clutch and took some pic's of the inside. NEVER apart! Original tailshaft seal/shift seals/side cover gasket etc. New seals are leaking. I KNEW I should not have used that oil. I was going to put it in the Rear Axle and Engine also. But might just forget it and send it back. $254 worth of oil and rear diff additive! I got talked into it by a friend. Is it ok to use in the engine with solid lifters, or the rear posi axle?
Danny

dannystarr

  • Hero Member
  • *****
  • Posts: 1347
    • View Profile
Re: Trans Shifting Issue
« Reply #4 on: May 27, 2018, 11:31:17 PM »
Got the linkage adjusted well. Even fine tuned it after this picture. So it isn't that... Danny

L78racer

  • Member
  • ***
  • Posts: 64
    • View Profile
Re: Trans Shifting Issue
« Reply #5 on: May 27, 2018, 11:58:08 PM »
send it back. use conventional oil and gear lube.
Paul

Stingr69

  • Hero Member
  • *****
  • Posts: 636
    • View Profile
Re: Trans Shifting Issue
« Reply #6 on: May 28, 2018, 12:13:15 AM »
Synthetic oil is probably so slippery the synchros will not work.  Drain and refill with conventional dinosaur oil.

68Zproject

  • Hero Member
  • *****
  • Posts: 1860
    • View Profile
Re: Trans Shifting Issue
« Reply #7 on: May 28, 2018, 12:31:22 AM »
Jerry always said NEVER use synthetic in the Muncie.  I use it in my 302 engine but I add the ZDDP plus to it.  I don't know about the rear and would like to know if synthetic is ok in that as well.  BTW it's a posi if that makes a difference.
68Z28

firstgenaddict

  • Hero Member
  • *****
  • Posts: 1930
    • View Profile
    • Groome Family Automobiles
Re: Trans Shifting Issue
« Reply #8 on: May 28, 2018, 12:32:55 AM »
The synthetics don't perform the same way... we have learned, tried them in multiple different 70's and older MT's and they do not shift right... the blockers or synchros don't slow down enough, it's as though the fluid does not cause enough drag due to low viscosity.

Newer transmissions are designed for use with low viscosity lubricants as the low visc lubes enable the vehicles to get better fuel economy.
James
Collectin' Camaro's since "Only Rednecks drove them"
 
Check out the Black 69 RS/Z28 45k mile Survivor and the Lemans Blue 69 Z 10D frame off...
https://plus.google.com/photos/112392262205377424364/albums?banner=pwa

bcmiller

  • CRG Member
  • *****
  • Posts: 2432
    • View Profile
Re: Trans Shifting Issue
« Reply #9 on: May 28, 2018, 03:41:10 AM »
As others have mentioned, use conventional oil ONLY!

Drain out what you have and get some regular gear oil.  I get mine at NAPA. Does not have to be a big name high dollar brand.  It is $6.99 per quart around here.   PART # NOL 75210

Put in conventional gear oil and your problems will most likely go away.
Bryon / 1968 Camaro SS 396 coupe - now 468 cubic inch BBC/M21
67 RS/SS 396 coupe L35/M40 - 4 generation family project
Looking for 68 Camaro with body # NOR 181016

RS Copo

  • Member
  • ***
  • Posts: 28
    • View Profile
Re: Trans Shifting Issue
« Reply #10 on: May 28, 2018, 06:55:06 PM »
Let us know how it works out. I have a friend who went to synthetic late last year and ran into the same problem.He is sure the trans has got other problems and it is not the oil causing it. Parked it,has not driven it at all this year.

Kelley W King

  • Hero Member
  • *****
  • Posts: 890
    • View Profile
Re: Trans Shifting Issue
« Reply #11 on: May 28, 2018, 08:34:12 PM »
Couple hundred miles just enough to dilute or wash off the old lube from the gears. You know what to do but the symptoms sound like low lube level.
69 Z28 RS Scuncio Hi Performance
69 SS L78
67 SS Chevelle
64 Corvette
66 GTO Tiger Gold
77 Trans Am Special Edition

joesauer

  • Member
  • ***
  • Posts: 172
    • View Profile
Re: Trans Shifting Issue
« Reply #12 on: May 29, 2018, 03:40:51 PM »
Ditto on the xmsn synthetic.....don't use it.  Conventional oil is better in old cars, including engine oil.

dannystarr

  • Hero Member
  • *****
  • Posts: 1347
    • View Profile
Re: Trans Shifting Issue
« Reply #13 on: May 29, 2018, 05:35:26 PM »
I still can't believe I did this >:(  I was told this 3 or 4 years ago to never use it. I bet it's in the old post from the other car? I just can't remember things since the surgery. I was under 5.5 hours, and I must have moved a little during the thyroid and 3 tumor removal. Then the surgeon must have scolded the anesthesiologist and he turned the knob and overdosed me with goop. After that, I was dizzy for 91 days! I lost a little that day  :(

 I KNOW it is full of oil. While filling it, it started coming out the fill hole. THEN I directed the nozzle to the tailshaft and cranked it 3 or 4 times. It was POURING out as I installed the plug.
Problem is how do I get it all out without pulling the trans? I can't get the side cover off and spray giant cans of carb cleaner in there to flush it down and out. I was going to drain it, then use the 80/90, then drive it for 10 miles, drain it again, add the 80/90 and see what happens. Or do that 3 TIMES! But won't the syn stick to everything? I better just pull it, drain it, spray it down. Flip it over a 5 gallon bucket like I did before. Rotate the assembly and keep spraying and bucket it again. Then add new oil and reinstall trans. SOB this sucks!!  Danny

Kelley W King

  • Hero Member
  • *****
  • Posts: 890
    • View Profile
Re: Trans Shifting Issue
« Reply #14 on: May 29, 2018, 06:35:21 PM »
I think you are overdoing it. Just drain it overnight, put the 90 weight in it and try it. Drive it through the gears when you do and let the oil get up in all the sliders,ect.
69 Z28 RS Scuncio Hi Performance
69 SS L78
67 SS Chevelle
64 Corvette
66 GTO Tiger Gold
77 Trans Am Special Edition

dannystarr

  • Hero Member
  • *****
  • Posts: 1347
    • View Profile
Re: Trans Shifting Issue
« Reply #15 on: May 29, 2018, 06:48:17 PM »
Can't drain overnight. M/21 has no drain plug, only fill plug. I was thinking of drilling the drain boss area and taping it. But I better not. Could devalue the original trans. I might try changing it twice like I mentioned and drive it and see what happens. Gotta get to a job... Danny

bcmiller

  • CRG Member
  • *****
  • Posts: 2432
    • View Profile
Re: Trans Shifting Issue
« Reply #16 on: May 29, 2018, 07:01:23 PM »
Use a pump to get the oil out. Put the hose in as much toward the bottom of the trans as you can. Pump it out. Wait a while until it drains a bit more, then pump it out again.

Honestly I think that will be enough. Then refill with regular gear oil.

Sorry to hear of your memory issues. It gradually happens to all of us as we get older.
Bryon / 1968 Camaro SS 396 coupe - now 468 cubic inch BBC/M21
67 RS/SS 396 coupe L35/M40 - 4 generation family project
Looking for 68 Camaro with body # NOR 181016

joesauer

  • Member
  • ***
  • Posts: 172
    • View Profile
Re: Trans Shifting Issue
« Reply #17 on: May 29, 2018, 09:28:58 PM »
Danny,

If you are still in Sonoma Cty., give Horgans Transmissions in San Rafael a call.  They may lend you the pump, etc. needed to get the synthetic out.   May have to leave them a deposit.

dannystarr

  • Hero Member
  • *****
  • Posts: 1347
    • View Profile
Re: Trans Shifting Issue
« Reply #18 on: May 30, 2018, 12:34:02 AM »
I am heading to Charlie's{Hubleyman} in Petaluma tom morn. What a blessing it was to meet him on THIS site. Hope he feels somewhat the same  :D
 He has helped me SO much. Going to put it up on the lift and change the oil, go for a drive and do it again. Oil is cheap enough. He has the pump there I think. I will update. Going to just stay with the High Zinc Lucas classic car motor oil also. Danny

dannystarr

  • Hero Member
  • *****
  • Posts: 1347
    • View Profile
Re: Trans Shifting Issue
« Reply #19 on: June 01, 2018, 06:30:53 AM »
UPDATE... Put the car on the lift and sucked out the synthetic trans fluid. Put in Sta-Lube/CRC 85/90 Multi-Purpose API/GL4 Gear Oil. Took the car for a 5 mile ride. Put the car back up and drained that out and filled again. Took a 10 mile ride down Hwy 101. Came back and sucked that oil out and filled with PennGrade 80/90 API GL4 Classic, Multi-Purpose Gear Oil. Shifts MUCH better and hoping it will get better with a little mileage and time. I will change it out again in 2 or 3 months. Still takes a little effort to get in to first gear at a stop. But not NEAR as much as before. I have become sort of an expert. Danny 

Kelley W King

  • Hero Member
  • *****
  • Posts: 890
    • View Profile
Re: Trans Shifting Issue
« Reply #20 on: June 01, 2018, 11:14:26 AM »
Drive it further. You want the oil to get hot and thin out to work up into the sliders and inside the brass rings. If you stick to short trips it could take a while but one long trip should do it. Even in neutral with clutch out most parts are rotating.
69 Z28 RS Scuncio Hi Performance
69 SS L78
67 SS Chevelle
64 Corvette
66 GTO Tiger Gold
77 Trans Am Special Edition

dannystarr

  • Hero Member
  • *****
  • Posts: 1347
    • View Profile
Re: Trans Shifting Issue
« Reply #21 on: June 01, 2018, 04:23:33 PM »
I figured, I may just put 100 miles on her over the weekend, then change it. We'll see... The main thing is, it looks like that was the issue, and it may only get better. Going to stick with the Lucas High Zinc for classic cars in the motor. Next week I will be changing the rear axle fluid with the Penn/Grade... D

olddragracer

  • Newbie
  • *
  • Posts: 7
    • View Profile
Re: Trans Shifting Issue
« Reply #22 on: June 01, 2018, 04:34:59 PM »
Sounds like you need to replace the clutch and pilot bushing. Try shifting into reverse while stopped, if transmission grinds after a short wait time clutch or pilot bushing dragging is your problem. If no grinding and reverse goes in smoothly maybe the  new lube is your problem.

dannystarr

  • Hero Member
  • *****
  • Posts: 1347
    • View Profile
Re: Trans Shifting Issue
« Reply #23 on: June 01, 2018, 07:31:04 PM »
Going in to reverse is SO sporadic it can't be used to diagnose. There are no synchros for reverse. Some days it drops right in, other days I put the trans in first and second two times then throw it in reverse. Other days I let the clutch out slightly and it drops in. Other days I move the car slightly forward in first gear FIRST, then throw it in reverse and it FALLS in. Both of my cars are different at any given time and condition. Replaced the Clutch/Pressure Plate/Throw-out Bearing/Pilot Bushing. Resurfaced the flywheel, as it had NEVER been touched. Still had the full side bevel, factory texture and of course, heat cracks. Danny
 P.S.
Olddragracer... welcome to the site! You have a Camaro?..

olddragracer

  • Newbie
  • *
  • Posts: 7
    • View Profile
Re: Trans Shifting Issue
« Reply #24 on: June 02, 2018, 01:07:58 AM »
It is true there is no syncro in reverse that is why you use reverse to diagnose a clutch release problem. Depress the clutch, engine at idle, wait 3 to 5 seconds depending on engine RPM, shift directly into reverse and if gears grind you have a clutch release problem!  The problems you describe are typical complaints for a clutch problem. Remember the pilot bushing, an old worn or a new but dry bushing can cause the transmission input shaft to turn with the engine causing problems you describe.   Yes I have a 67 coupe I have been working on for a very long time

bcmiller

  • CRG Member
  • *****
  • Posts: 2432
    • View Profile
Re: Trans Shifting Issue
« Reply #25 on: June 02, 2018, 04:00:49 AM »
UPDATE... Put the car on the lift and sucked out the synthetic trans fluid. Put in Sta-Lube/CRC 85/90 Multi-Purpose API/GL4 Gear Oil. Took the car for a 5 mile ride. Put the car back up and drained that out and filled again. Took a 10 mile ride down Hwy 101. Came back and sucked that oil out and filled with PennGrade 80/90 API GL4 Classic, Multi-Purpose Gear Oil. Shifts MUCH better and hoping it will get better with a little mileage and time. I will change it out again in 2 or 3 months. Still takes a little effort to get in to first gear at a stop. But not NEAR as much as before. I have become sort of an expert. Danny 

Seriously, you donít need the expensive gear oil. In fact, the cheap stuff I mentioned is actually what I have found to work BEST. 
Bryon / 1968 Camaro SS 396 coupe - now 468 cubic inch BBC/M21
67 RS/SS 396 coupe L35/M40 - 4 generation family project
Looking for 68 Camaro with body # NOR 181016

dannystarr

  • Hero Member
  • *****
  • Posts: 1347
    • View Profile
Re: Trans Shifting Issue
« Reply #26 on: June 02, 2018, 04:48:00 AM »
Oh ok, my mistake. I will try that over the weekend. Took it for a ride tonight about 70 miles. It DID seem like a clutch issue at first but then it works perfectly when the car is rolling. I mean it FALLS into gear just as long as you are moving at least a mile an hour. So I figured it was releasing enough. I have it adjusted with about an inch and a half play. Might change that to the standard inch next time it's in the air. I do know the fluid played a part of this. Maybe not all of it, but surely some of the issue. Cause nothing else was changed. Thanx for your time everyone on this... Danny

bcmiller

  • CRG Member
  • *****
  • Posts: 2432
    • View Profile
Re: Trans Shifting Issue
« Reply #27 on: June 02, 2018, 05:10:06 AM »
You have changed it twice already. I would say keep what you have in there for a few MONTHS and then maybe change again.

Changing to standard clutch adjustment may help a bit too. What clutch are you running?
Bryon / 1968 Camaro SS 396 coupe - now 468 cubic inch BBC/M21
67 RS/SS 396 coupe L35/M40 - 4 generation family project
Looking for 68 Camaro with body # NOR 181016

Stingr69

  • Hero Member
  • *****
  • Posts: 636
    • View Profile
Re: Trans Shifting Issue
« Reply #28 on: June 02, 2018, 12:34:35 PM »
The clutch free play is supposed to be 1" at the pedal, measured with finger pressure.  If you adjust it with 1.5" of free travel it will not be releasing all the way and it will be difficult to get into reverse.  Fix that first adjustment and see if it helps.

olddragracer

  • Newbie
  • *
  • Posts: 7
    • View Profile
Re: Trans Shifting Issue
« Reply #29 on: June 02, 2018, 02:10:34 PM »
The clutch free play of 1 inch is used to allow for wear of the clutch components in particular the disk. As wear occurs free play diminishes.  Setting the free play near zero and driving the car [normal driving] will allow you to see if setting of free play or amount of pedal travel is your problem. If pilot bushing or clutch itself is the problem the minimal free play usually does not help the problem. Do not try hard acceleration with minimal free play as clutch damage can occur.

z28z11

  • Hero Member
  • *****
  • Posts: 1215
    • View Profile
Re: Trans Shifting Issue
« Reply #30 on: June 02, 2018, 04:44:49 PM »
While we are discussing trans and diff lubricants, anyone old enough to remember why you had to add a bottle of limited slip lubricant to the rear (after the late 60's ?). Hint - Something was taken out of the gear oils used with positractions.

Good Double Bonus question -

Regards,
Steve

1968 Z28 M21/U17 BRG/W
1969 Z28 X77/M20/VE3 LeMans/W
1969 L78 X66/N66 Cortez/BVT
1969 Z11 L48/M35/C60/C06

olddragracer

  • Newbie
  • *
  • Posts: 7
    • View Profile
Re: Trans Shifting Issue
« Reply #31 on: June 02, 2018, 05:38:11 PM »
The additive was used to modify the slip factor of GL4 lubricant, increase its slip factor, and stop the limited slip clutch plates from chattering going around corners. Whale oil was used in the additive. The use of whale oil stopped with the whaling ban.  The new stuff has never worked as good.   my opinion

olddragracer

  • Newbie
  • *
  • Posts: 7
    • View Profile
Re: Trans Shifting Issue
« Reply #32 on: June 02, 2018, 05:40:40 PM »
additive has been used since the 1950's

z28z11

  • Hero Member
  • *****
  • Posts: 1215
    • View Profile
Re: Trans Shifting Issue
« Reply #33 on: June 02, 2018, 10:27:32 PM »
You are correct - my first posi (69 Z) was my intro to the additive. Amazing to believe whale oil was ever used at all -

Wikipedia states the ban went into effect in 1972, prior to that 30 million pounds a year were used for transmission fluids and gear oils.

Regards,
Steve
1968 Z28 M21/U17 BRG/W
1969 Z28 X77/M20/VE3 LeMans/W
1969 L78 X66/N66 Cortez/BVT
1969 Z11 L48/M35/C60/C06

69Z28-RS

  • Hero Member
  • *****
  • Posts: 4784
  • owner since 4-Apr-1976
    • View Profile
Re: Trans Shifting Issue
« Reply #34 on: June 03, 2018, 03:57:01 AM »
I bought a few bottles  (which I still have) from my local Chevy parts store before they all disappeared...  :)

Gary W / 09C 69Z28-RS, 72 B 720 cowl console rosewood tint
69 Corvette convertible, silver/black 350 hp,
60 Corvette white/red, 72 Corvette coupe, '70 Mach I 
90 ZR1 red/red #246, 90 ZR1 white/gray #2466
72 El Camino, '55-'56-'57 Nomads, '55-'57 B/A Sedan

ZLP955

  • Hero Member
  • *****
  • Posts: 1531
    • View Profile
Re: Trans Shifting Issue
« Reply #35 on: June 03, 2018, 05:48:32 AM »
Whale oil..... might explain why used rear end oil used to stink so much.
Tim in Australia.
1969 04A Van Nuys Z/28. Cortez Silver, Dark Blue interior, VE3 bumper, Z21, Z23, D55/U17, D80, flat hood.
Sold at Clippinger Chevrolet in Covina, CA. Ex-E/MP at Lions Dragstrip in Long Beach.