Shifting on a J.D. 770

[robmc]

Good evening all, My name is Rob and this is my first thread on your forum. I just picked up a '92 770 compact tlb. It runs and operates quite well, and would say it is in good overall condition, however I am finding myself grinding the gears. I am typically doing this going from 1st to reverse in high range, all though I also find it happening shifting into other gears. It doesn't do it all the time, I just cant seem to find a sweet spot. Do I need a clutch?
Thanks in advance.

 

[SHORT KID]

Your clutch may just need adjustment. Next time you are operating, make sure you are fully depressed on the clutch and completely stopped before shifting.You may even apply the brakes to make sure you are completely stopped. Good Luck

 

[Bandsaw]

I have a 650. If i am running the pto it takes a second after i depress the clutch for the pto to slow down

 

[robmc]

Thank you for your replies. I'll get out there today and make sure I am completely stopped. Hopefully that helps.

 

[Don87]

I saw a post somewhere one time, where the person said that 'double-clutching' would stop the gear grinding when shifting up thru the gears. It has an unsychronized transmission(kinda like a tractor-trailer).

 

[droptop]

Shifting a 770 on the fly is tough and takes a lot of practice and still isn't 100%. Best to stop and shift until you are more comfortable and experienced with it.

 

[Chilly807]

Any unsynchronized trans will grind if you shift on the fly without double clutching, mine is the worst when I go to engage any gear from neutral. I find it helps if I press the clutch in, wait 5 seconds, then engage a gear. That allows the transmission shafts to come to a stop and no grinding will occur.

The trouble with double clutching a tractor is you have very little momentum to carry you while you shift, I usually only shift on the fly between 3 high and 4 high.

Sean

 

[robmc]

Thanks again to all of you for your feedback. I was able to get on the tractor today and I did what you folks recommended. It was considerably better. You have to wait a few seconds before you engage. I really have to send that clutch home however. Is that normal? (There is consistent pressure through the whole stroke of the pedal.)

 

[SHORT KID]

One other thing I forgot to mention in my earlier post, after you are done shifting take your foot completely off the clutch pedal.You probably already knew this but if you are busy and doing a lot of back and forth, one tends to forget. I had some problems with seat adjustment on mine because of my short legs.

 

[arrow]

Thanks again to all of you for your feedback. I was able to get on the tractor today and I did what you folks recommended. It was considerably better. You have to wait a few seconds before you engage. I really have to send that clutch home however. Is that normal? (There is consistent pressure through the whole stroke of the pedal.)

Greetings fellow Fosterite. I would heed the earlier suggestion from Short Kid and take up some of your clutch adjustment. If its anything like my 750, there should only be about a half to an inch of free play before it engages. If you are engaging too close to full pedal, then you need the adjustment. I am not sure which shifter you have but if its a synchronous, even if it allegedly is able to shift while moving, I'd still come to a stand still if I'm grinding gears. Check the clutch travel at any rate.

 

[crashz]

If you have a dual stage clutch, you must press the pedal all the way down to disengage. With a dual stage clutch, the first half of pedal travel disengages the PTO, the second half disengages the transmission.

I tend to slip up once and a while by either not coming to a full stop or not fully depressing the clutch.

 

[Chilly807]

My dual stage clutch engages the PTO first off the floor, then engages the drive wheels as you reach the upper end of the pedal travel.

Sean

 

[mroldstyle]

My dual stage clutch engages the PTO first off the floor, then engages the drive wheels as you reach the upper end of the pedal travel.

Sean

Mine too, that way the implement keeps running full speed while you ease out the clutch to begin travel

 

[crashz]

You guys are correct. I stated it backwards.


Hmm - I do know that if I don't clutch all the way before going from a forward gear to reverse, I get a grind. But that doesn't make sense. Hmmm.