FJ40 grinds gears when shifting into 1st or reverse

[Reeve Kook]

I have a 1973 fj40 with the factory f engine, and 3 speed tranny. When going into 1st gear or reverse under any condition, the tranny makes a “grinding gears noise” which is felt in the shifter. After holding the shifter there, the grinding noise slows down until it pops into gear. I have a feeling this has something to do with the clutch and not the transmission. It is also worth noting that when in gear and holding the clutch in for a long period of time, the clutch slowly grabs and the vehicle slowly begins moving, until the clutch is all the way seated on the flywheel while the clutch pedal is to the floor. I have replaced the clutch slave cylinder, so I have a feeling it is the clutch master cylinder that is in need of a rebuild. I just want a confirmation that this is what is happening, or possibly any other ideas why this is happening, thanks!

 

[whitey45]

Sounds like the clutch master is bleeding down. Also no synchro on first or reverse so any disc engagement will make it that much more unlikely to engage smoothly. A trick is to put it in 2nd gear first to slow down the input before selecting 1st gear.

 

[brian]

standard procedure is to hit 2nd before dropping into either 1st or R.
and yes the master needs replaced as well.

 

[Reeve Kook]

I was poking around under the car whilst replacing the cam in the engine and decided to take that plate that covers the bottom of the clutch and flywheel, and I noticed 3 fingers, at the end of those fingers was bolts that looked like they need to be set at a set distance, They have a decent gap and they are most certainly not at the same position. Pretty sure that this is contributing to the problem a decent portion, right? Here is a picture I found off the internet to show what I'm talking about in case you are lost.

 

[B y r o n]

What you have is a Long style pressure plate and the adjustment bolt you're pointing to can be a different heights from the levers. There adjustment deals with constant and equal pressure on the clutch disc.

If the clutch is depressed and you can't get it into 1st or Reverse it is because the master or slave are defective.

 

[nachohouse]

Reviving this thread because I have a similar issue and thought the advice here about the master and slave were sound. I rebuilt my master with an OEM kit (bore was in great shape, no pitting at all), replaced the slave and the rubber clutch line with a new one from cityracer. I did a thorough bleed and am confident there is very little, if any, air in the system. Clutch pedal feels pretty much the same and I still get some intermittent grinding when shifting into first or reverse from stop.

Does the column shift linkage need adjusted? Looking for some additional advice. Thanks.

 

[brian]

Reviving this thread because I have a similar issue and thought the advice here about the master and slave were sound. I rebuilt my master with an OEM kit (bore was in great shape, no pitting at all), replaced the slave and the rubber clutch line with a new one from cityracer. I did a thorough bleed and am confident there is very little, if any, air in the system. Clutch pedal feels pretty much the same and I still get some intermittent grinding when shifting into first or reverse from stop.

Does the column shift linkage need adjusted? Looking for some additional advice. Thanks.

first and reverse in the three spd is unsynchronized .

 

[Grayscale]

@nachohouse The three speed lacks synchronizers on the first gear. So, you need to stop the spinning components inside the box. When the vehicle is stopped, and in neutral, press down on the clutch pedal, shift to second, then shift to first or reverse, ease off the clutch as normal. As long as you are in neutral, w/o depressing the clutch pedal, parts are spinning.

The trick is downshifting into first. The vehicle is in motion, not stopped. I could never get it just right. Someone will hopefully chime-in with double-clutching

They (your passengers) used to say something like, 'grind 'em 'til you find 'em.' Funny, 'til you drain the gear oil from the transmission, and look at the solid contents on bottom of the catch-pan.

 

[brian]

@nachohouse The three speed lacks synchronizers on the first gear. So, you need to stop the spinning components inside the box. When the vehicle is stopped, and in neutral, press down on the clutch pedal, shift to second, then shift to first or reverse, ease off the clutch as normal. As long as you are in neutral, w/o depressing the clutch pedal, parts are spinning.

The trick is downshifting into first. The vehicle is in motion, not stopped. I could never get it just right. Someone will hopefully chime-in with double-clutching

its all about the throttle blip

 

[Skreddy]

Reviving this thread because I have a similar issue and thought the advice here about the master and slave were sound. I rebuilt my master with an OEM kit (bore was in great shape, no pitting at all), replaced the slave and the rubber clutch line with a new one from cityracer. I did a thorough bleed and am confident there is very little, if any, air in the system. Clutch pedal feels pretty much the same and I still get some intermittent grinding when shifting into first or reverse from stop.

Does the column shift linkage need adjusted? Looking for some additional advice. Thanks.

There’s the slave cylinder pushrod adjustment and an adjustment at the pedal pushrod where it goes into the master cylinder.

Otherwise ya, non-synchro can often have grinding.

 

[charliemeyer007]

When the engine rpm exactly matches the tranny speed shifting down from second to first is grindless and requires practice to get it right. Never learn to drive your own old Ferrari - yes it will be a gear bashing adventure because none of the gears had syncros - better to learn on someone else's.

 

[1911]

When the engine rpm exactly matches the tranny speed shifting down from second to first is grindless and requires practice to get it right. Never learn to drive your own old Ferrari - yes it will be a gear bashing adventure because none of the gears had syncros - better to learn on someone else's.

Same with old Indian motorcycles.

 

[POPO AGIE]

I almost bought a old CJ5 that had a Ford 289 and the T90 transmission.
When I took it for a drive I found that first gear was not synchronized and the seat was set permanently to far forward so my shins were right at the bottom of the dash where the metal was bent 90 degrees. Between the no low end torque and not synco transmission I passed.

Much rather finish my FJ40 then have bought that CJ.

 

[timmyisinthewell]

I own a '54 Kaiser Darrin with a Borg Warner T96 three speed w/overdrive. Syncros on second and third only. "Double Clutching" is the way.

 

[Living in the Past]

The FJ25 has a four speed and transfer case that only engages the front driveshaft. No low range. Those only third and four are synchronized. Also all the gears are straight cut. All thru the 1970s I drove multiple type of stick shifts in commercial trucks. Most with two speed rear axles. Being able to double clutch became second nature. When I installed H42 into my 68 FJ40 in the 1990s on mid forest service roads would practice shifting gears without using the clutch. Had to do that with the column shift three once. The H42 is simple compared to that. Never owned a VW Beetle but did test drive a Porsche 912 once. Linkage was worn out and finding a gear was next to impossible. Did end up with a Datsun 260Z 2+2. My then wife made sure I didn't get to keep that very long. Even before I was married between her and my parents for me to sell my 69 Opel GT and buy a new 73 Monte Carlo. Never missed the Monte Carlo or my ex. Just wish I still had the Opel GT. 74 I bought my 68 FJ40. Had buy it again in the divorce but I still have.

 

[POPO AGIE]

I put a lot of miles on my 4-speed without using the clutch. Once the RPMs are right it shifted great going up or down.

 

[charliemeyer007]

Momentary kill switch can aid shifting.

 

[Living in the Past]

Momentary kill switch can aid shifting.

Don't understand the kill switch. Down shifting you speed the rpm up the match what how fast the lower gear is spinning at the same speed a lower gear has higher RPM which your trying match to have the shifter collar slip into that lower gear. The FJ25. Going from the first gear which a granny gear second gear will a lower RPM at that speed. Really don't double clutch as engage the clutch and wait for the RPM to drop so the shift collar will slip into second gear without grinding. In most cases you used drove like a three speed second thru forth gears. The first gear was available in 2WD and 4WD. On the three speed to get that low of gear required going into 4WD. I know it is easy to remove the shift gate or twin stick but Toyota didn't design the aluminium transfer case to be used in 2WD low range. On the FJ25 the transfer case is cast iron.

 

[charliemeyer007]

I used a kill switch on my Yamahahammer to shift up while laying on the tank and clutching the cafe bars.

 

[Grayscale]

So, I should throttle-blip a H42-4-speed, tcase, when going from 4-high to 4-low? Is this different in some way?

I'd bet that a winter-cold gear box with synchros, downshifting does better with throttle-blip? The oil is too slippery for synchros, when it is at colder/greater-visocosity?

And, in a similar sentiment, some folks warm their gear-oil up with the transfercase in neutral, the gearbox in 4th, iirc. and, of course, the e-brake is on.

So, even for us 4-speed H42 drivers, at a stop-light turned green, we can put less stress on the first-gear-synchro by shifting from neutral into a taller gear, like 4th, and then, while still holding the clutch peda downl, shift into first? (Because the clutch-disk is still spinning at 600 rpm in neutral, and that is closer-rpm-matched to a stationary fourth gear, than it is matched to first?)