At 0.086 in. backlash I'd be looking for a set of final drive gears to go with the sprocket and hub. Just what CC threw away....maybe:D

This tractor has seen a hard life.....do you know any of its history??

Ok, Old Magnet I was measuring the wrong thing. I was measuring the gap between the nut and sprocket. I will have to remeasure (correctly) tomorrow. I understand what I am supposed to measure now. Please don't yell at me- I'm new at this and anxious to learn! After all, this thing was built almost 30 years before I was born!

I am pretty concerned about this backlash issue now. I used a magnetic base and dial indicator also. Everytime I try to move the sprocket in a forward and backward direction (determining the "slop") I get between .070 and .090 - in other words about 5/64 of an inch.

CCJersey- do you still have bull gears and pinions! I may well take you up on some of these parts. Do you have any experience in checking this backlash issue?

Went for $.08 a pound (net to us $.04)

I have kept that chunk of 9U for 10-15 years and a brake band was the only thing that anyone ever got off it. The transmission that was attached had gotten full of water and locked the whole business up. It originally had a Hyster towing winch on the back, but I couldn't convince "the powers that be" to save that as well. Now I really wish I had it.

I have other parts 9U dozers if you can't find something locally.

G'day Guys,

Would you have some specs for the D4, and upgrade for bellow seals?

Hi Joel,
to more accurately check the F/D back lash you will need to push the inner sprocket hubs' taper roller bearing up into it's cup fully and squarely to align the center line of the hub to the dead axle. This in turn will set the bull gear( as the big sprocket hub gear is known here in OZ) in it's correct relationship with the mating pinion, there by allowing the correct B/L to be measured.
With the hub hanging loosly down you will indeed measure a lot larger B/L.
You also should be able to remove what appears to be an extra drain plug in the rear face of the final drive housing and better inspect the gear teeth. The extra plug is due to the one case fitting both left and right sides of the machine.
Hope this helps.
Cheers,
Eddie B.

Hi edb,
What would you consider a reasonable range of back lash to be??

Also can't seem to find a torque spec for the sprocket retainer nut (for the D6 or D5)
Maybe it's not critical....got any info?? Thanks

Hi OM,
how long is a piece of string?
To answer your query we must take into account that the brake should be applied or the brake drum rigidly held so as to not get a false reading from turning the pinion and taking the free play of :-
(1) the clutch discs to the drum splines, inner and outer in the steer clutch.
(2) any possible slop in the splined joint of the pinion shaft and the pinion flange--brake drum bolts to this. Because the sprocket joint was loose whoever assembled this side F/D may not have pressed any of the joints, so we need to be careful here.
(3) that the sprocket hub and its taper roller bearing are fully seated as described by me in a post above.

As the sprocket is larger in dia. than the F/D bull gear we will measure a larger than actual dimension at the sprocket tooth than is actually at the gear teeth. All that aside I feel something in the order of 0.040"-0.080" at the sprocket would be around 0.020"-0.060" at the gear teeth.
I had always rattled the sprocket after assembling a F/D but never measured the clearance, but kind of knew it was ok as I had put in serviceable gears.
Naturally there is a difference between a F/D with a single reduction compared to one with intermediate pinions to give extra back lash just to confuse it further for me to state a reliable clearance.
I would suggest as the F/D is all but dismantled that the case be removed and the tooth condition be ascertained. By the junk in the pix I would expect a fair amount of wear from dirt, but for a hobby machine I feel it would not be too critical.

OM
your actual B/Lash measurements are the only sure comparison to go by here. I have done this sort of thing when we had dirt ingress problems with Mitsu excav and early 200 series excav. F/D's.
I think I have only confused things here with my ramblings but however any input to the discussion is to advantage to give a clearer overall picture.

Tension at the Dealer was the same as for outer bearing adjustment---using the 7F9306 heavy duty castleated nut spanner wrench we put on a 6 foot piece of pipe and had one person bouncing on the end of same until the nut was tight--this would have been in the order of 600-700 lbs feet. For a D7 or early D8 we would have 2 persons on the pipe.
As the sprocket is supposed to be pressed on the torque of the sprocket retaining nut is not so critical as the press fit keeps the sprocket on its hub.
Hope this helps.
Cheers,
Eddie B.

Hi Team,
just got back from youngest Grandson's Kindergarden (pre-school) Nativity Play, was great to see all nationalities of kids having fun.

Any way just looked in my D7 17A (I think) Serv. Man. and it says to tighten the sprocket retaining nut as tight as possible with the 7F9306 adjustable wrench, so that tallies with what I posted above.
My D6 U series Serv. Man. does not mention refitting the nut at all!!!! after pressing the sprocket to 30 tons.
Cheers for now,
Eddie B.

edb,

thanks for your expertise in this matter. It does help a lot. I was trying to remember the Mathematics classes that I took in high school and college. I was thinking there was a relationship between getting a bigger measurement at the top of the sprocket as there would be at the gears themselves. This is certainly a hobby machine and not a daily user. In the summer time it gets used maybe 3 to 5 hours per week. I am going to pull the final drive case and inspect the gears (with pictures) as soon as I can get to it. Maybe tonight.

Old Magnet,

I'm really thinking that I'm going to be looking for a sprocket and hub. I will check the correct measurements tonight. On the machine's history- The machine came from Rhode Island (I had it trucked here to western NY). It was used on a pig farm and was supposed to be a 1 owner machine believe it or not. The man was in his 80's and clearing out his machinery. It was supposed to have 4700 hours on it. I take all of that with a grain of salt so to speak. From what I have found with the machine, the owner took good care of the easy-to-do things like oil and filter, fuel filters and such. However he wasn't to good about maintaining important things like final seals and track adjuster bolts!

Keep those thoughts and ideas coming. Thanks everyone.

Hi Joel,
Yes, might as well pull the case as it looks like you will need to anyway.
I would still get both the sprocket fit and back lash measurements anyway, just to see where your at......plus I'd like to have the information:D

edb,
Thanks for the info......way more science than I was utilizing for just a "rough and dirty" check. I'd still like to see tighter clearances the 1/16 in. as these gears are already subjected to heavy shock loading.

Odd that Cat would not specify a torque for the retainer nut, they seem to cover most everything else.

I rely heavily on the D6 37A/44A service manual for power transmission information applicable to the "U" model D6
It has a lot more information and detail than the "U" model service manual....including excellent coverage of the duo-cone finals seals. I also noticed that Cat kind off backed off on the requirement for the seal installation tools as they probably weren't getting used anyway.