David brown 990 trans clutch won't disengage

[Agri–Mechanics]

We've just picked up a clutch job on a dB 990 someone else stripped we've put a new transmission clutch in it and refit however it won't release. The fingers are pushed in when the clutch is off and there's a massive gap between the clutch fingers and bearing it only just contacts the fingers on full travel. Could we have fitted the plate the wrong way round or am I missing something else.. like I said we didn't strip it we got the job after someone else.. I'm splitting it again tomorrow but any advice would be helpful as never done one of these before it's the twin plate clutch with a separate PTO clutch lever

 

[john432]

Must be a 996 ,990 and 995 had the PTO clutch on the second stage down on the pedal.

 

[ACEngineering]

We've just picked up a clutch job on a dB 990 someone else stripped we've put a new transmission clutch in it and refit however it won't release. The fingers are pushed in when the clutch is off and there's a massive gap between the clutch fingers and bearing it only just contacts the fingers on full travel. Could we have fitted the plate the wrong way round or am I missing something else.. like I said we didn't strip it we got the job after someone else.. I'm splitting it again tomorrow but any advice would be helpful as never done one of these before it's the twin plate clutch with a separate PTO clutch lever

Has it got little clips to hold it compressed while fitting like nuffield/leyland double clutch has? If so have they been removed after fitting?

 

[Bald n Grumpy]

We've just picked up a clutch job on a dB 990 someone else stripped we've put a new transmission clutch in it and refit however it won't release. The fingers are pushed in when the clutch is off and there's a massive gap between the clutch fingers and bearing it only just contacts the fingers on full travel. Could we have fitted the plate the wrong way round or am I missing something else.. like I said we didn't strip it we got the job after someone else.. I'm splitting it again tomorrow but any advice would be helpful as never done one of these before it's the twin plate clutch with a separate PTO clutch lever

Have you tried adjusting the pedal free play either on the pedal without q cab or rod in slave cylinder if q cab
Otherwise sounds like the clutch needs resetting to bring the fingers closer to the bearing
As john 432 said if it's got a pto hand clutch it's a 996

 

[Phil P]

We've just picked up a clutch job on a dB 990 someone else stripped we've put a new transmission clutch in it and refit however it won't release. The fingers are pushed in when the clutch is off and there's a massive gap between the clutch fingers and bearing it only just contacts the fingers on full travel. Could we have fitted the plate the wrong way round or am I missing something else.. like I said we didn't strip it we got the job after someone else.. I'm splitting it again tomorrow but any advice would be helpful as never done one of these before it's the twin plate clutch with a separate PTO clutch lever

Chances are the pedal has been backed off as the clutch has worn, if I remember right there’s adjustment on the bottom of the pedal. There’s also some setting studs on the pressure plate that need setting but I can’t remember the tolerance but it came on the instructions in the kit.
In the kit I had there was some little plastic wedges that dropped out once the pressure plate was clamped up, they where pretty obvious though.

I did once go to a David Brown that someone had put a new clutch in but had fitted the friction plate backwards then wound it back together, the result wasn’t good!

 

[agrimax]

If someone has replaced the PTO clutch and reinstalled the toggle lever springs in the wrong position, the toggles will be compressed before the release bearing touches them.

 

[Bald n Grumpy]

Chances are the pedal has been backed off as the clutch has worn, if I remember right there’s adjustment on the bottom of the pedal. There’s also some setting studs on the pressure plate that need setting but I can’t remember the tolerance but it came on the instructions in the kit.
In the kit I had there was some little plastic wedges that dropped out once the pressure plate was clamped up, they where pretty obvious though.

I did once go to a David Brown that someone had put a new clutch in but had fitted the friction plate backwards then wound it back together, the result wasn’t good!

Your picture shows a clutch from a DB without a pto hand clutch they are quite different

 

[Phil P]

Your picture shows a clutch from a DB without a pto hand clutch they are quite different

Ye, I re read the op’s post then realised, I’m no db expert . But the free play bit is relevant.

 

[Boohoo]

Must be a 996 ,990 and 995 had the PTO clutch on the second stage down on the pedal.

Independent pto was available on late model 990s.

 

[Agri–Mechanics]

Has it got little clips to hold it compressed while fitting like nuffield/leyland double clutch has? If so have they been removed after fitting?

Hi ace no clips the three fingers on the outer pack hold it all together with a few short bolts around casing

 

[Agri–Mechanics]

I tried adjusting the free play out of it at the slave cylinder but ran out of rod it's almost as if the clutch is compressed but don't know what would cause it I'll grab some pictures today once it's split again at least it's quick to split

 

[Agri–Mechanics]

Found theproblem looks like the pins under the arms had sheared off only one was still in place so no tension on the plate new pressure plate ordered