Manual Transmission - shifter vibrates and hard to get into gear

[tadaima]

Hey Everyone, Happy Holidays.

I just got another car again. Its a SR5 1985 Corolla 5spd.

I noticed that the shifter vibrates a lot at high speeds, and that it is really hard to get the car into first gear, well any gear except reverse at times.

Doesnt seem to be related to cold temperature, i could have the car warm and it will have problems getting into gear. Usually I have to get it into a lower gear before I completely stop at a stop sign, or I'll have problems getting into gear.

I am going to change the tranny oil this weekend and hope that it will cure the shifting problem, though I dont think it will solve the vibration coming from the shifter stick.

Any ideas? Bad U joint?

Thanks

 

[Gary Allan]

Q: If you're just sitting there at idle with the clutch IN ..does it grind going into reverse if you do it slowly (no matter how long you leave the clutch in)?

The only reason at I ask is that you report that ALL forward gears give you difficulty and it is eased with the vehicle in motion. If this was a cable or mechanical linkage clutch ..I would say that you had a shot pressure plate ...if it's hydraulic ..I would think that this is "THIS" part of your problem. The motion thing would allow the engine speed and the gear blocker rings to be "in sych" at, at least, one point in the coasting event.

This, however, should have nothing to do with the vibrating stick. My only experience with a vibrating stick was with my 77 Chevette.

Sit at idle with the clutch out ..listen ...push clutch in ..is it quieter? If you have a worn input bearing you will hear a sound like a muffled idling diesel (very muffled and distant).

My $0.02

 

[tadaima]

Gary,

Wow very descriptive.

Actually just drove it off for lunch. Yes it is quieter when i push on the clutch pedal.

And yes it grinds into reverse, when I feel it grinding, I clutch several times and then try slowly again.

Wonder if changing of the tranny fluid help?

Thanks

 

[tadaima]

Hmm input bearing, well let me ask how much that will be to replace.

I assume the hydaulics and the input bearing is two different issues?

Again yes I hear the muffled distant Diesling sound.

IT actually give a whine in 5th gear around 65mph.

 

[Mike_dup1]

Trans has to come out.

Might just as well replace the clutch as that may be the problem. Trans could have problems but if the shifter is rattling, it could have worn parts etc.


Important - How many miles on vehicle?

Cost - Varies but could be easy $500+ providing there are not other problems. If high mileage vehicle, may not be worth the cost.

[ December 26, 2003, 05:07 PM: Message edited by: Mike ]

 

[tadaima]

Well the chasis has 235K, the 4ac engine has about who knows, a used engine was put in 1995 at 181K, so it has roughly about 50K on the used engine, the tranny has never been changed so it probably has the original 235K in it, though clutch was replaced in 2000.

 

[Robbie Alexander]

quote:

---

Originally posted by tadaima:
Well the chasis has 235K, the 4ac engine has about who knows, a used engine was put in 1995 at 181K, so it has roughly about 50K on the used engine, the tranny has never been changed so it probably has the original 235K in it, though clutch was replaced in 2000.

---

Yup, a new pressure plate, and berings with a disc should set you up fine. Might as well change the fluid, and the front seal to the tranny while youre there, along with the rear main... no use having to go there again/

 

[Gary Allan]

quote:

---

when I feel it grinding, I clutch several times and then try slowly again.

---

Okay ...IF this is a hydraulic clutch ..this still could be the hard shifting thing. Since you apparently (or so I gleaned from the above quote) have an easing of the grinding into reverse with a "pumping" of the clutch ...I'd say that you may need a new slave or clutch master cylinder.

..again if it's a cable (not too stretched) or mechanical linkage ..the pressure plate is the most likely cause. The springs are shot and when you push in on the fingers via the trowout bearing ..you're only partially engaging it (I never liked the nomenclature of "engaging and disengaging" the clutch when you're engaging and disengaging the connection between the engine and the trans. The functional terms are in conflict with each other. That is, when you "engage" the clutch ..it's no longer "clutching" the disk. When you disengage the clutch ...it's "clutching"

).


The rattle at idle is the input bearing (as others have confirmed). I've lived with this condition for 50k or more. The vibration does mean that there is some imbalance under load (possibly the wobble from the worn input bearing). Since you have this vibration ..you probably will wear the gear set if you continue to run this in this condition. Again ..is it going to render the vehicle undrivable?? Probably not for a great while.

Changing the gear oil removed the debris that has made your ball bearings "smaller" or develop flat spots. It won't fix anything ..but will help slow the rate of decay.

I'd search for another trans. Have that visually inspected before install (perhaps to the point of putting new bearings in it

even). Then, as others have suggested, do the whole 9 yards (clutch, pressureplate, rear main ..etc..etc.). In this fashion you keep the vehicle in service until the day(s) of installation.

It all depends on how much you want to keep this econo-box running. If you're otherwise happy with it ...go for it. If it's degraded from reliable beater to unreliable beater ...

 

[Gary Allan]

quote:

---

I assume the hydaulics and the input bearing is two different issues?

---

Sorry ..I skipped your second posting there

Okay ...I'll give you a little man/tran 101

The hydraulic clutch is a clutch actuation modality that has come back into vogue lately. It operates just like your brakes. A clutch "master" cylinder is actuated by the floor pedal and this motion is hydraulically transmitted to a "slave" cylinder that attaches to the lever that actually moves the clutch mechanism locally at the bellhousing. These hydraulics fall prey to all the ailments that brake hydraulics do. Internal and external leaks ..etc. If the bore is worn on either the master or slave cylinder ...fluid simply passes around the cylinder, either partially or completely (extreme case). Typically if this is the case at the slave cylinder ..it externally leaks. The master cylinder piston merely sends it back to the resevour (usually).

The input bearing supports the input shaft. It's a ball bearing ..just like virtually any bath lubricated application (air compressors, industrial pumps, etc.) The shaft is subjected to both reactive and helical loads. The gears want to spread appart in opposite directions laterally (up and down) ..and, due to the tooth pattern, wants to send the shafts in opposite directions, front and rear (this is called helical load).

check this out if you have time. How Stuff Works

 

[tadaima]

Gary,

Thanks for the 101.

Well Had the tranny oil changed today, and it was pretty clean, but used 75w90 penz synth. And that cleared up the 1/2nd gear shift issue ...well to some degree, at least it goes into gear from a stop.

Reverse is still grinding, so I will look into making a decision on what to change based on your info.

As for the vibration while driving coming from the shifter, that has mellowed with the changing of the fluid. Maybe it was just a bit low or something.

CLUTCH master and slave cylinder has been replaced like 1yr ago, and fluids look good.

So looks like pressure plates, and bearing!!!

 

[tadaima]

Hmmm, you know what, it shifts into reverse a lot better if not always.. when I go into 1st then reverse, it doesnt say anything in the manual to do this...though I vaguely remember that I had to do this with older cars, also with german cars I have to push down on the stick before going into reverse...could this have been my problem the whole time???

If it is..i feel so stupid, though I probably should change some tranny parts...well just got this car last week anyways.

 

[Gary Allan]

By going into 1st gear first you will stop the input shaft ..so you will not grind going into reverse IF the clutch is working properly AND the reverse idler is in such a position that it will allow engagement. Going into reverse always results in some gear clash (typically). I believe that my owners manual recommends a rather "abrupt" or "rapid" movment from neutral to reverse. This minimizes the grinding.

Reverse is not sychronized (typically ..but some company is doing this on a late model)..there would be no use for this unless you were a stunt driver that needed to go into reverse when the car is rolling forward.

 

[tadaima]

Gary,

Thanks for the help you are very insightful, well looks like the whole day today by going into first and then going to revers has no problems, also the 1st/2nd gear rough shifting is going away.

One thing still remains is that when coasting around a corner downshifting from 3rd to 2nd can be a bit rough, not necessarily a grind, but more like going through a notch.

Well hey this car is 20yrs old and it has 235K on the tranny...should I expect more? =)

Been a while since I had a carbed car, had many motorcycles, should I expect this corolla to idle perfectly smooth like a EFI engine?

I changed the ignition coil, dist cap, rotor, spark plug wires, spark plugs, figure the only thing that can cause a bit of roughness is some slightly leaking vacuum hoses, but it just idles okay, but sounds like it misses a heartbeat every 15-20sec of idling.

I could clean the carb intake butterfly, that's the last thing i've done. But from my experience with old motorcycles, I dont think I've ever heard a carb fuel system run perfectly smooth unless I increase idle by a lot. I know that on motorcycles rejetting is definately a necessity when going from certain temperature and altitude client, as for a car engine there's vacuum sensors and stuff to compensate for it.

 

[eljefino]

Are you letting the clutch out in neutral before attempting first or reverse (double-clutching)?

Not necessary when new, it helps with bad syncros.

 

[tadaima]

Usually no, I will shift into 1st and then shift into reverse, if it gives problems, then I will.