763 Bobcat noise -pump, tensioner or other?

[429ford]

Hello, new to here, and fairly new owner of the earlier model (rectangle headlight) 763. 5300 hrs. Have had the machine for about a year. Love it, was told 3rd owner. First was a lumber co? Was very clean doesn't look like been in manure or anything. Was traded back to dealer at 5100 hr. Local menonite changed all filters and fixed all he saw was wrong. Put 80 hrs on it to verify all worked well and resold (does a few a year for extra cash). I have put about 100 hrs on it. Other day I noticed as was lifting high to dump, the "pump" light flicked on and right back off. Checked fluid level, was ok. Had a slight rattle? type noise. Thought was fan tensioner pulley, as it seemed to bounce alot. Took apart, seems fairly tight. Put back together and ran OK, about same. Today, maybe -2 hours since apart, as idling hear a noise. Similar to before, just louder and on off. Like 5 seconds noise then 5-10 without then again?? No problems noticed, just noise? Sorry so long, just wanted to give all the info I could. Any ideas?

 

[Tazza]

I'd think it could be the blower?. The gearbox on them do go out and can rattle a lot as the gears wear.

 

[429ford]

I'd think it could be the blower?. The gearbox on them do go out and can rattle a lot as the gears wear.

The blower as in radiator fan? And what gearbox would you be talking about? The drive or hydraulic? Sorry, just not real familiar with it. It makes the noise even when setting still. I let it set and run, and looked in trying to see if I could see or hear where it may be from. No luck.

 

[429ford]

The blower as in radiator fan? And what gearbox would you be talking about? The drive or hydraulic? Sorry, just not real familiar with it. It makes the noise even when setting still. I let it set and run, and looked in trying to see if I could see or hear where it may be from. No luck.

Just did some more checking. Seems as though when it makes the noise bad, I can watch thru air outlet on side and see the fan jump up and down at least a half inch!!

 

[Tazza]

Just did some more checking. Seems as though when it makes the noise bad, I can watch thru air outlet on side and see the fan jump up and down at least a half inch!!

That is the fan i was talking about, it cools the oil cooler and radiator.
Moving that much isn't right.... Hopefully the damage isn't too bad.

 

[7LBSSMALLIE]

That is the fan i was talking about, it cools the oil cooler and radiator.
Moving that much isn't right.... Hopefully the damage isn't too bad.

the coolining fan gear box. A.pully in or out should be about 4to 6 thous end play. same for fan up or down simple ring and pinion set up to change backlash is a matter of addining shims. unfourtantley no l onger avail. a resourcefull man . bench iit tear it down clean it up. shim as needed. (speedy sleeves are avail. if to loose use Loctite 660} shim as needed. (even if you have to fabricate) put back . priced anew one yesterday 751.00.

 

[429ford]

the coolining fan gear box. A.pully in or out should be about 4to 6 thous end play. same for fan up or down simple ring and pinion set up to change backlash is a matter of addining shims. unfourtantley no l onger avail. a resourcefull man . bench iit tear it down clean it up. shim as needed. (speedy sleeves are avail. if to loose use Loctite 660} shim as needed. (even if you have to fabricate) put back . priced anew one yesterday 751.00.

Wow, that's pricey. And mine looks to be at least 1/2" up and down. So, hope its not toast. Noise just became noticeable above motor drone. Don't know how long before that. What is the best way to get to this to pull out? Looks like if you can get behind seat and thru there it would be easiest? Wish I would have gotten a repair manual. Found a parts manual online.

 

[7LBSSMALLIE]

Wow, that's pricey. And mine looks to be at least 1/2" up and down. So, hope its not toast. Noise just became noticeable above motor drone. Don't know how long before that. What is the best way to get to this to pull out? Looks like if you can get behind seat and thru there it would be easiest? Wish I would have gotten a repair manual. Found a parts manual online.

before I would condem that I would bench the drive belt idler and check it out early models were a constant tension. new spring loaded the little pointer thing likes to break making a god awul sound .

 

[429ford]

before I would condem that I would bench the drive belt idler and check it out early models were a constant tension. new spring loaded the little pointer thing likes to break making a god awul sound .

I've had the tensioner off the fan drive belt, it is not too bad. But if I understand you correct, you mean the main drive belt tensioner? For the flat belt? It appears tight and all, but maybe something in there? I really believe after finding the fan, that appears to be the noise. When it starts moving around (up and down quite a bit) is when you hear the noise. I see this post is in the wrong area also (sorry, im a newbie) will post in correct section.