Synthetic in auto trans
YukonGMC
08-14-2005, 11:23 AM
Is this recommemded ? I changed over to Mobil 1 ATF in my 2001 YXL. 5.3, I'm not sure if I have a 60 or 80 AT. For the first few weeks it shifted as smooth as silk. No problems beforehand either. Now it's a little rougher. 1st seems to take longer to shift and going into 2nd and 3rd seems to be a rougher shift. The GM mechanic did add a can of some kind of conditioner when he flushed and refilled with Mobil 1. If I had watched him I would have passed on the conditioner. Anyone else experienced this ? I did not change filter and this was done at 16K miles. Kind of wish I had saved my 185 bucks.
eljones247
08-15-2005, 08:25 PM
Is this recommemded ? I changed over to Mobil 1 ATF in my 2001 YXL. 5.3, I'm not sure if I have a 60 or 80 AT. For the first few weeks it shifted as smooth as silk. No problems beforehand either. Now it's a little rougher. 1st seems to take longer to shift and going into 2nd and 3rd seems to be a rougher shift. The GM mechanic did add a can of some kind of conditioner when he flushed and refilled with Mobil 1. If I had watched him I would have passed on the conditioner. Anyone else experienced this ? I did not change filter and this was done at 16K miles. Kind of wish I had saved my 185 bucks.
I have heard of this in higher mileage transmission. I have heard guys with the same problems with standard ATF also.
It is known that flushing can sometimes cause some trash to be knocked loose in the system during a power flush. A trany guy told me he recommended changing the filter after the flush so the lose particles aren't in the filter media until the next service.
I have also read that any service to the transmission COULD be flirting with disaster. They talked about introducing contaminates to the system as well as disturbing the internal contaminates, in turn can be worse. They talked about higher mileage trasmitions benefited from the unserviced fluid due to a thicker viscosity as compared to the thinner clean fluid. I believe Ford has started extending service to 100k and in some applications lifetime service. If I were you, I would service @ 50k towing or not.
In my past experience, a hard / late shift is due to low fluid or a broken servo spring. Your governor may also be sticking. Not sure if back in 2001 they were still installing adjustable TV cables or not; but if they did and it was out of adjustment, it could also cause it.
I have heard of this in higher mileage transmission. I have heard guys with the same problems with standard ATF also.
It is known that flushing can sometimes cause some trash to be knocked loose in the system during a power flush. A trany guy told me he recommended changing the filter after the flush so the lose particles aren't in the filter media until the next service.
I have also read that any service to the transmission COULD be flirting with disaster. They talked about introducing contaminates to the system as well as disturbing the internal contaminates, in turn can be worse. They talked about higher mileage trasmitions benefited from the unserviced fluid due to a thicker viscosity as compared to the thinner clean fluid. I believe Ford has started extending service to 100k and in some applications lifetime service. If I were you, I would service @ 50k towing or not.
In my past experience, a hard / late shift is due to low fluid or a broken servo spring. Your governor may also be sticking. Not sure if back in 2001 they were still installing adjustable TV cables or not; but if they did and it was out of adjustment, it could also cause it.
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