CAT 130G Transmission trouble?

Hi all, I have a Cat 130G with trans pressure dramas in Clutch 7 when hot. I have done all the pressure checks cold everything is just within the specs. When everything is hot and you do the checks again, I have significantly low mains pressure whenever i have clutch 7 engaged at low idle. I.E Neutral, 4,5,6 in both FWD and REV. If go to high idle. the pressures jump up to normal. In all other gear selections all pressures are just within the minimum spec. I feel that the piston seal may have failed, but i can't understand why it doesn't show this when cold as well. To give some context on the problem the machine has around 22000hours. The original complaint from the operator was when he went to go roading home after a days work he had no gear 4,5,6 unless at full engine speed. The S/N is 12W00786. Anyone have any ideas? Thanks in advance.

Does the transmission oil smelled burned.? Are you using TO-4 oil SAE 30 or 50.? Is it dark in colour instead of being clear & bright.? Is there anything in the suction screen(s).? How are you measuring the clutch pressures.? IIRC the procedure calls for removing the driveshaft. I suppose the alternative is to jack up the tandems and sit it on blocks. CRC CAT D5K2 said: I have done all the pressure checks cold everything is just within the specs. Click to expand... How about posting some actual numbers.? CRC CAT D5K2 said: In all other gear selections all pressures are just within the minimum spec. Click to expand... That in itself tells a story. CRC CAT D5K2 said: To give some context on the problem the machine has around 22000hours. Click to expand... Long past time the transmission was rebuilt in that case, unless it was rebuilt some time previously. CRC CAT D5K2 said: I feel that the piston seal may have failed, but i can't understand why it doesn't show this when cold as well. Click to expand... Depending on what oil you are using (see earlier question) the pump may just be able top keep up with the leakage when the oil is cold and heavy, not so much when it gets hot and thins out.

Trans oil is TO-4 30. Its clear and not burned. Suction screens are clean. Suggest to me that oil has been changed recently. Mains pressure 335PSI cold. Mains pressure 85PSI hot with clutch 7 engaged. As soon as you go to high idle you get about 325PSI. If you engage 1,2,3 FWD or Rev pressure on the mains jumps from 85 to about 325PSI. Transmission was previously rebuilt at about 8000hours by Hastings Deering, upgrades apparently also at that point. I am checking the pressure with the tandems blocked up. I would agree pump can't keep up with the losses when hot, trying to narrow down the points for the losses. Looking at SIS I can't see parts listed but there must be rotating seals on the main shaft for that clutch also. Thanks for your reply.

If you want to try a dice throw before making the decision to pull the tranny why not dump some SAE50 TO-4 in it for a test.? If the symptoms take longer to appear from cold then I would say that you have confirmed an internal leak somewhere in either the rotating seals or the piston seal for #7 clutch. A long shot but have you confirmed that the adjustment of the speed/direction cables is correct.?

I have indeed replaced the balls and bolts and pins at both ends of the cable and corrected adjustments. No change from before the repairs. Am currently getting some quoted for parts bearings/seals. No one seems to have a reman trans here in au any more. Best i can come up with is a core return for $8000. Thanks.

If you have a half-decent shop there is really nothing to fear in tearing into one of these transmissions yourself. There is nothing really complicated inside one. Help via the internet is available should you go that way.

I have checked some prices here for a bearing kit, seal kit and all plates and discs. Aftermarket that runs to about $6500. Genuine cat parts are about $12500. That's not even looking at the pump parts yet. Are parts this expensive in the US? I found a mob here called Tilly's have a exchange reman trans for $22000. It's not going to be cheap.........

At 1.5 AUD to the USD those parts prices look not too far off the mark.

Nige said: At 1.5 AUD to the USD those parts prices look not too far off the mark. Click to expand... All parts are scary. Guy runs the 180 volvo loader in the quarry. Takes away from the crusher, loads trucks. A 180 is just as fast as an L70. He keeps the pit floor like a paved road, and he's always full speed. Some of the stock piles are aways from the crusher. The 999,999 trip across the pit with his bucket close to the ground, he caught up. There is a large wishbone. Tilt piston on one end, rod to the bucket on the other pivot in the middle. Broke that. It was 20,000, and volvo was having som type of sale on parts. $$$$$

So did you get anywhere with this transmission.?

Not as yet, the owner is still deliberating the costs. I suppose its hard to justify spending $10K plus on parts and then labour on top for a machine that's only worth around $25-30K. Especially when it still operates fine in the lower speeds. I will let you know what is going to happen. Thanks.