390T knock when turning

maco2000

Hi folks, We recently purchased a 1994 MF 390T 4WD and on occasion when turning either left or right from the road into the yard there is a bang/jolt coming from the front of the tractor and I'm just wondering has anyone else experienced this? It has been back to the dealer that we purchased it from a couple of times now and the problem still persists. The first time a universal joint on the front right wheel was changed and the second trip consisted of the solenoid being rewired on the transmission for the front wheels. There had previously been a DIY job done on it with a wire running from the switch in the cab down to the solenoid switch. Now on contacting the dealer we're being told that it's "normal" for this to happen and it's just the 4WD engaging on braking when turning............just wondering is this the case on all 4WD 390T's or is there something more sinister going on in the guts of the front axel? Any help would be greatly appreciated. Thanks.

Reggie.

maco2000 wrote: »

Hi folks, We recently purchased a 1994 MF 390T 4WD and on occasion when turning either left or right from the road into the yard there is a bang/jolt coming from the front of the tractor and I'm just wondering has anyone else experienced this? It has been back to the dealer that we purchased it from a couple of times now and the problem still persists. The first time a universal joint on the front right wheel was changed and the second trip consisted of the solenoid being rewired on the transmission for the front wheels. There had previously been a DIY job done on it with a wire running from the switch in the cab down to the solenoid switch. Now on contacting the dealer we're being told that it's "normal" for this to happen and it's just the 4WD engaging on braking when turning............just wondering is this the case on all 4WD 390T's or is there something more sinister going on in the guts of the front axel? Any help would be greatly appreciated. Thanks.

That's the dog clutches not disengaging after being the brakes were applied. It's a common fault in the front axles of them. That wiring job was probably the homemade switch to turn off the front braking at the clutches. It is quite common as mine has the same setup. Mine will bang when turned on and will stop when the switch is turned off.

Your better off getting it sorted as it will put pressure on your hub seals and blow them over time and they are €90 apiece. If you have to replace them go genuine as otherwise you'll be changing them for sport.

smokey-fitz

Good man reggie! have the same issue myself with the 4355 for a while, so its probably the same kind of set up. Thought it was to do with the brakes because it usually happens after braking when turning and is coming from the front.

Reggie.

smokey-fitz wrote: »

Good man reggie! have the same issue myself with the 4355 for a while, so its probably the same kind of set up. Thought it was to do with the brakes because it usually happens after braking when turning and is coming from the front.

When it happens on mine the two front hubs hop a little bit.

jimmy G M

We had something similar on our 4255 4 wd. 4 wd engages when you hit the breaks, pain when you are turning and hit the breaks at the same time, eg turning in a gate and breaking at the same time. Leads to excessive tire wear as well.

Dealer we bought from put in a switch to stop the 4 wd engaging when breaking, so we now have the option to turn off if not required. Off most if the time except when hauling slurry tanker.

Base price

This is a really stupid question but how is the 4wd engaging by itself when ye put your foot on the brake

jimmy G M

Base price wrote: »

This is a really stupid question but how is the 4wd engaging by itself when ye put your foot on the brake

It's to ensue 4 wheel braking, without the need for brakes in the front. Rear wheels are braked, 4 wd engages, front wheels break also. Improved braking traction esp in field work.

Base price

jimmy G M wrote: »

It's to ensue 4 wheel braking, without the need for brakes in the front. Rear wheels are braked, 4 wd engages, front wheels break also. Improved braking traction esp in field work.

Thanks jimmy. I wouldn't be used to the workings of more "modern" tractors other than driving them and knowing where the diesel/engine fillers are - me been a stereotypical female driver

maco2000

Reggie. wrote: »

That's the dog clutches not disengaging after being the brakes were applied. It's a common fault in the front axles of them. That wiring job was probably the homemade switch to turn off the front braking at the clutches. It is quite common as mine has the same setup. Mine will bang when turned on and will stop when the switch is turned off.

Your better off getting it sorted as it will put pressure on your hub seals and blow them over time and they are €90 apiece. If you have to replace them go genuine as otherwise you'll be changing them for sport.

Thanks a million, that sounds like they already had a fix in place and we got them to take it out. Didn't know why there was a rogue wire coming down from the cab to that solenoid switch! What's the best solution to go with so, wire the switch back in to turn off the front wheel braking? Dealer told us to knock the piers going in the gate! ☺ Looks like a common enough problem so at least everyone is in the same boat. I was really worried about turning the hay and such that it would be banging at every turn in the field! At least it only happens under braking so will be more manageable. Cheers again!

Reggie.

maco2000 wrote: »

Thanks a million, that sounds like they already had a fix in place and we got them to take it out. Didn't know why there was a rogue wire coming down from the cab to that solenoid switch! What's the best solution to go with so, wire the switch back in to turn off the front wheel braking? Dealer told us to knock the piers going in the gate! ☺ Looks like a common enough problem so at least everyone is in the same boat. I was really worried about turning the hay and such that it would be banging at every turn in the field! At least it only happens under braking so will be more manageable. Cheers again!

Def put the switch back in. Nearly every 300 series I've seen has the switch in them

maco2000

Reggie. wrote: »

Def put the switch back in. Nearly every 300 series I've seen has the switch in them

Thanks again, if only I'd posted on boards first I would have left it in!

Reggie.

maco2000 wrote: »

Thanks again, if only I'd posted on boards first I would have left it in!

Its a learning curve for everyone