Slow speed dilemma

[RonAus]

Hi all, Having checked the travelling speed of my 763 which should be 7 MPH (11.2 KPH), I have ascertained that it is only doing 4.5 MPH when on full throttle (7 to 8 KPH). It does not appear to have any belt squeal when moving and I have confirmed it does the same speed forwards and backwards. Any ideas as to why would be very much appreciated.

 

[Fishfiles]

maybe add a nitro bottle and you would be ready for the 1/4 mile

 

[RonAus]

maybe add a nitro bottle and you would be ready for the 1/4 mile

Whilst I appreciate the attempt at humour, the max speed that I could achieve is half that of what I believe the machine is capable of, certainly it is 20% lower than the travelling speed mentioned in the manual. I am trying to resolve the problem and get the machine back to proper operating levels, so instead of any comments welcome perhaps I should have asked for serious answers welcome.

 

[sstec]

Whilst I appreciate the attempt at humour, the max speed that I could achieve is half that of what I believe the machine is capable of, certainly it is 20% lower than the travelling speed mentioned in the manual. I am trying to resolve the problem and get the machine back to proper operating levels, so instead of any comments welcome perhaps I should have asked for serious answers welcome.

I don't care who you are, THAT"S FUNNY. . . . . .

 

[sstec]

I don't care who you are, THAT"S FUNNY. . . . . .

Now all BS a side. . . . My 873 will show signs of slow, sluggish travel with any air intro to the system, leaks or low fluid level. sstec

 

[skidsteer.ca]

Now all BS a side. . . . My 873 will show signs of slow, sluggish travel with any air intro to the system, leaks or low fluid level. sstec

It still pushes hard when digging?
A belt that sliped that bad just driving would stall the pump completely under a load and the the chge presure warning shoud come on.
Wonder if it somehow got larger displacement wheel motors installed?
Skidsteer.ca

 

[RonAus]

Now all BS a side. . . . My 873 will show signs of slow, sluggish travel with any air intro to the system, leaks or low fluid level. sstec

Thanks for the info, I did not even think to check the levels. I will have to go through the basic abc's from scratch. Not sure how to check for air in the system though. It would have been funnier to me if it had been after your or someone else's advice. Thanks

 

[RonAus]

Thanks for the info, I did not even think to check the levels. I will have to go through the basic abc's from scratch. Not sure how to check for air in the system though. It would have been funnier to me if it had been after your or someone else's advice. Thanks

I must admit I did not try digging yet but when I start it and push on the pedals or pull on the lever, it sometimes try to stall or does unless I pull/push the levers a little first, then it is okay. Sometimes I have to increase the revs and still push/pull the levers first. There is no squeal like a belt slipping so I did not consider that and from what I know of the machines history of two previous owners that are less likely than me to change the displacement wheels, but how could I check anyway?

 

[Fishfiles]

I must admit I did not try digging yet but when I start it and push on the pedals or pull on the lever, it sometimes try to stall or does unless I pull/push the levers a little first, then it is okay. Sometimes I have to increase the revs and still push/pull the levers first. There is no squeal like a belt slipping so I did not consider that and from what I know of the machines history of two previous owners that are less likely than me to change the displacement wheels, but how could I check anyway?

all pun aside ------------speed is achieved by flow ( GPM) not pressure (PSI) , power is achieved by pressure , with that thought in mind the problem seems to be a flow issue as you say the levers are center where as it does the same speed in forward or reverse , the left side and right side travel have their own supply pump and motor for each side , you didn't mention the machine hooking to either side so both sides are effected the same , as Ken said it is possible both travel motors have been changed as there are 4 different motors that were used over the years in that model machine , some problems would be the drive belt , engine rpm's , linkage , travel motor seals , sunstrand or the charge pressure -------I think I would open the case drain filter and check for debree such as orings , back up rings or metal , then I would drain the hydraulic filter into a clean container and if I seen any amount of flakes I would cut the filter open and unfold the element to look for golden flakes which would be signs of the rotator group tearing up in side the Sunstrand transmission pump -----does your machine drip oil from under the pintle levers , it may be sucking in air -------does your machine have the 10-16.5's or does it have the 12-16.5's ------------- whilst ( I like that word ) I was browsing , I seen a guy on this site , I believe , that put a V-8 in his Bobcat

 

[RonAus]

all pun aside ------------speed is achieved by flow ( GPM) not pressure (PSI) , power is achieved by pressure , with that thought in mind the problem seems to be a flow issue as you say the levers are center where as it does the same speed in forward or reverse , the left side and right side travel have their own supply pump and motor for each side , you didn't mention the machine hooking to either side so both sides are effected the same , as Ken said it is possible both travel motors have been changed as there are 4 different motors that were used over the years in that model machine , some problems would be the drive belt , engine rpm's , linkage , travel motor seals , sunstrand or the charge pressure -------I think I would open the case drain filter and check for debree such as orings , back up rings or metal , then I would drain the hydraulic filter into a clean container and if I seen any amount of flakes I would cut the filter open and unfold the element to look for golden flakes which would be signs of the rotator group tearing up in side the Sunstrand transmission pump -----does your machine drip oil from under the pintle levers , it may be sucking in air -------does your machine have the 10-16.5's or does it have the 12-16.5's ------------- whilst ( I like that word ) I was browsing , I seen a guy on this site , I believe , that put a V-8 in his Bobcat

Hi Fishfiles, Okay I asked for it and you delivered lol. you have certainly given me a lot to look at and check. I will check the levels first, the rpm's seem quite okay, just as good as the 753, both motors operate at the same speed with no pull off to any side, the linkage is something that could be next and then on to the next one your list which I will print out. BTW I will admit, it was funny. Also, regarding the 10-16.5's or 12-16.5's, what are they? A V8, I know I want to go faster but I think that is overkill lol. Even though I should know, as a complete novice and never having gotten into doing repairs until very recently, I am going to have to read the manual and find out where the case drain filter is, plus the hydraulic filter etc. Thanks again.

 

[Fishfiles]

Hi Fishfiles, Okay I asked for it and you delivered lol. you have certainly given me a lot to look at and check. I will check the levels first, the rpm's seem quite okay, just as good as the 753, both motors operate at the same speed with no pull off to any side, the linkage is something that could be next and then on to the next one your list which I will print out. BTW I will admit, it was funny. Also, regarding the 10-16.5's or 12-16.5's, what are they? A V8, I know I want to go faster but I think that is overkill lol. Even though I should know, as a complete novice and never having gotten into doing repairs until very recently, I am going to have to read the manual and find out where the case drain filter is, plus the hydraulic filter etc. Thanks again.

10 (width) x16.5 (rim) is the normal tire on a 763 , but some 763 machines have the 12x16.5 as you can fit them on that machine , or do you have some type of specialty tire such as solid , segmented or whatever that may have a different OEM diameter which may effect the speed --------the case drain filter is inside of a round aluminum casing about 1.5 inch diameter and 3 inches long , there will be one 3/8 inch hose going in and one going out , that machine may have one on the bottom of the hydraulic tank and one on the small hose off of the travel motor , inside is a bronze coloered rock filter , two springs and a couple of orings , this filter catches the trash , be sure you note how it came apart and put everything back in the same way , the hydraulic filter would be on the top right hand side of the engine compartment --------------if the linkage has a lot of wear in the bushings and bolts then it might not be getting the full monty ( stroke ) -------------------ever heard of the New Orleans Saints NFL football team , thats my home boys , they will be on today at 12 noon and I'll be sucking down some brews " whilts " eating some boiled shrimp and sticked shrimp on the bar'bie ---------thats for the word of the day

 

[Jyuma]

10 (width) x16.5 (rim) is the normal tire on a 763 , but some 763 machines have the 12x16.5 as you can fit them on that machine , or do you have some type of specialty tire such as solid , segmented or whatever that may have a different OEM diameter which may effect the speed --------the case drain filter is inside of a round aluminum casing about 1.5 inch diameter and 3 inches long , there will be one 3/8 inch hose going in and one going out , that machine may have one on the bottom of the hydraulic tank and one on the small hose off of the travel motor , inside is a bronze coloered rock filter , two springs and a couple of orings , this filter catches the trash , be sure you note how it came apart and put everything back in the same way , the hydraulic filter would be on the top right hand side of the engine compartment --------------if the linkage has a lot of wear in the bushings and bolts then it might not be getting the full monty ( stroke ) -------------------ever heard of the New Orleans Saints NFL football team , thats my home boys , they will be on today at 12 noon and I'll be sucking down some brews " whilts " eating some boiled shrimp and sticked shrimp on the bar'bie ---------thats for the word of the day

Hello RonAus... just in case... the 10-16.5's and 12-16.5's are tires sizes.
bTw... Nitro bottle? You had to of laughed at that one...

 

[RonAus]

Hello RonAus... just in case... the 10-16.5's and 12-16.5's are tires sizes.
bTw... Nitro bottle? You had to of laughed at that one...

Hi fishfiles, I thought the dims would be tyres but did not want to make the statement, lol. I will check but I think the tyres are 16's . Thanks for the info, that makes life a lot easier and doable, Not heard of your team but definitely a shrimp on the barbie if you remember the Paul Hogan adverts. I hope your team wins and you enjoy the beer and shrimp. Thanks again.

 

[RonAus]

Hi fishfiles, I thought the dims would be tyres but did not want to make the statement, lol. I will check but I think the tyres are 16's . Thanks for the info, that makes life a lot easier and doable, Not heard of your team but definitely a shrimp on the barbie if you remember the Paul Hogan adverts. I hope your team wins and you enjoy the beer and shrimp. Thanks again.

I meant 12

 

[RonAus]

I meant 12

Hi Jyuma, I did laugh after a while, and thanks.

 

[Tazza]

Hi Jyuma, I did laugh after a while, and thanks.

You state that it still drives straight, so i would like to think they pumps are still pretty good. When they wear, its not usually the same amount on both sides.
You say it does bog down, are you talking the engine or the main drive? Even scooting along with no load and a slightly slipping belt you shoudl get full speed.
There really isn't a whole lot else that could slow it down, motor and pump wear is really about it. I assume you checked the linkages? they are tight? The arms where they pass through the plate near your feet, they aren't touching the plate when you move the sticks forward or backwards? The shock absorbers could be an issue, but again, doubtful.

 

[RonAus]

You state that it still drives straight, so i would like to think they pumps are still pretty good. When they wear, its not usually the same amount on both sides.
You say it does bog down, are you talking the engine or the main drive? Even scooting along with no load and a slightly slipping belt you shoudl get full speed.
There really isn't a whole lot else that could slow it down, motor and pump wear is really about it. I assume you checked the linkages? they are tight? The arms where they pass through the plate near your feet, they aren't touching the plate when you move the sticks forward or backwards? The shock absorbers could be an issue, but again, doubtful.

Hi Tazza, In terms of bogging, it is only when I first get in, it does not happen when I am moving and when I have tested the speed, it is not under load and I cannot hear any squeal. I have just thought of something but I would be surprised if it is this, Where the machine is, the guy who is storing it, put on a 4 in 1 bucket and when I have tested it, I have left it on. As I said it is unlikely but I mention it as a thought. The linkages seem clear apart from when I lift the cab up and the hand grip catches on the after market air con unit, I was thinking of trying to bend the arm a little to clear it. FYI when I received the email advising me of your comment, the following line was in it but missing in the forum when I logged in "I should check what speed my machine does, see if its the same as you are getting or not. It may be normal." If you do check or anyone else has checked their machine, I would really appreciate the results.

 

[Tazza]

Hi Tazza, In terms of bogging, it is only when I first get in, it does not happen when I am moving and when I have tested the speed, it is not under load and I cannot hear any squeal. I have just thought of something but I would be surprised if it is this, Where the machine is, the guy who is storing it, put on a 4 in 1 bucket and when I have tested it, I have left it on. As I said it is unlikely but I mention it as a thought. The linkages seem clear apart from when I lift the cab up and the hand grip catches on the after market air con unit, I was thinking of trying to bend the arm a little to clear it. FYI when I received the email advising me of your comment, the following line was in it but missing in the forum when I logged in "I should check what speed my machine does, see if its the same as you are getting or not. It may be normal." If you do check or anyone else has checked their machine, I would really appreciate the results.

Yeah, i took that part out as i got it confused with another post of a user with an S150, My 763 is still in bits.

 

[Fishfiles]

Yeah, i took that part out as i got it confused with another post of a user with an S150, My 763 is still in bits.

I read some of the post again and I was just thinking about something that happened to me with a S series machine and I would guess that a late production date of a 763 may have had the same thing , under the seat , in what I call the cowl , there are two hidden holes that are covered with plastic plugs , under those plugs you can use an allen wrench to get to a bolt which acts as a adjustment -limiter , and I seen where the part the allen screw threads into breaks off and screws up the travel of the lever movement , I would doubt it could happen on both sides at the same time , but maybe if the machine was equipment with that and they were out of adjustment it could be an issue