790 and 3005 Hydraulic Shimming

[RoyJackson]

I just added 1 shim pac to my 3005. Original pressure was 2150psi. After adding the shim pac it was 2500psi. As noted the results were modest but noticeable. I am going to add a few more shims to shoot for 2900 psi. I am trying to lift small scrub trees out of the ground and feel I need just a bit more power.

The caution for me seems to be that the entire design and balance of the tractor does not seem to be happy swinging and lifting big loads in the front. With 2500 psi and a stubborn tree root I feel I am at near the limit of the overall tractor design. I used a 3000 psi gauge on an 18" long piece of prefabricated hydraulic hose and a male quick connect coupling to read the pressures at the connection point of the front bucket. Note that there are several styles of quick connect couplings that look very similar but only the exact one will mate up.

I really wouldn't add more then one pack...but if you do, the risk is on you...

 

[dirt ditch]

If you feel you are near the limit of the overall tractor design of the tractor what is the point of exceeding it with risk of injury or breaking the machine. I added a pack of shims 5-6 years ago and got 2400 psi with them. My 790 has 6-60lb rear wheel weights and my ballast box weights I think over 800lbs. I have used my JD 790/300 with a 485lb set of Horst forks to lift a 920lb JD MP72 skid steer bucket on a pallet into the back of my pickup. That is over 1400 lbs and the relief valve did kick in before the loader got it high enough to clear the bed. Had my wife operate the tractor while I picked up on the front of the forks to help the hydraulics get the clearance needed. I had the truck backed up to the pallet and ready to go so after picking it up I backed the truck under the pallet then set it down. No way I'd move the tractor with that much weight sticking out in front. I now have a set of forks for my skid steer and don't have to worry about over loading the tractor loader.

 

[dieselcrawler]

I like the sounds of this mod... where do I get the shim kit? Lift ability could stand a boost.

 

[BigEddy]

There's a reason the pressure limits are set where they are.

 

[dieselcrawler]

Yup... but they set the limits for the operators that dont have common sense to pay attention to their mechine and just blindly use them. My diesel trucks all came from the factory without the chips and gauges I have added.... chips for added power, gauges to pay attention to how the added power is effecting the truck.

I understand the potential... both positive and negative, in this situation. I also plan to add a turbo to my fine lil 3005... but both mods will wait untill the warrentee runs out!

 

[dirt ditch]

where do I get the shim kit? Lift ability could stand a boost.

You get 4 shims in a bag. Here is JD part number. 1 pack worked for me but like Roy said "the risk is on you..."

View attachment 345827

 

[dieselcrawler]

I understand the risks. Thanks for lookin out for me and the words of caution. I'll look into the shim kit next chance I get...

 

[dieselcrawler]

Bringin this back to the top...

Ordered and installed the shim kit... will find out the results next time I get to use the tractor. Just finished installing about 20 minutes ago after the evening feeding trip to the barn...

 

[YesDeere]

You will be happy

 

[dieselcrawler]

Wish I had a gauge to have checked before and after psi. Where would I check psi if I could find a gauge to use?