The Classic Machinery Network

Can I use EP90 instead of HD90 ? I've got 3 litres in the store already. After all, its been running on water for the last 10 years...

My plate was just the same,as were the bolts. Pretty sure it must be frost damage- like a glacier trying to escape! I 'repaired' mine on an anvil and stuck it back on, and filled with oil. Been fine since.

That makes perfect sense. I was baffled until I realised that most of the "oil" was actually water. I'll stick the plate in my hydraulic press and flatten it. Hopefully the bolts will come out with a a stud remover bit.

I'll stick some EP90 in it and Bobs your dads brother...

Emptied the slew actuator, and there was no oil in it at all, it was all water... Just a bit of soft oil bits. Ive flattened out the plate and its just had a coat of acid etch primer on it, before I spray it up JCB yellow. 5 litres of EP80/90 gearbox oil was £11 plus the vat, so nice and cheap.

Now, I want to replace the bolts as they are bent and there are only two left. The old snapped ones came out easily without any tools, just finger tight. They are 3/8 by 1inch, I think, and the spanner size is 9/16. Just had a look in the manual and they are UNF.

Ebay I think...

Bolts arrived this morning. Manual says UNF but its not whats fitted, so does anyone know what thread they could be. UNF is quite a fine thread, but the bolts I took out are a lot more "open threaded."

Any ideas before I reorder off Ebay ??

EDIT: I think its UNC.. Im slowly understanding this old school imperial stuff now.

Tillywolves wrote:Bolts arrived this morning. Manual says UNF but its not whats fitted, so does anyone know what thread they could be. UNF is quite a fine thread, but the bolts I took out are a lot more "open threaded."

Any ideas before I reorder off Ebay ??

EDIT: I think its UNC.. Im slowly understanding this old school imperial stuff now.

Hi there while I don't know what thread your bolts are you could save yourself a lot of trouble if you bought some imperial and metric thread gauges and a Zeus book from an engineers merchants then you could identify most threads very easily, just an idea.

UNF equals fine thread; UNC equals course thread (American threads)
BSW equals course British Standard Whitworth and BSF equals British Standard Fine (not common these days)
And also Metric fine and course threads

Jeremy

Tillywolves wrote:Bolts arrived this morning. Manual says UNF but its not whats fitted, so does anyone know what thread they could be. UNF is quite a fine thread, but the bolts I took out are a lot more "open threaded."

Any ideas before I reorder off Ebay ??

EDIT: I think its UNC.. Im slowly understanding this old school imperial stuff now.

They will be UNC bolts if its 3/8 diameter and a 9/16 head and I can see the thread is course
all very interesting to a non JCB owner


Paul

Thanks Jeremy. I have been working at JCB today, and one of the guys there explained the different threads... A gauge was one of the things recommended.

I use metric all day, and the strange selection of imperial sizes sometimes baffles me...

Four nice new stainless steel UNC bolts arrived this morning. Filled up the gearbox with 4.5 litres of EP90, and fitted the nicely painted plate, using a bit of liquid gasket sealer...


Original URL: http://i893.photobucket.com/albums/ac137/tillywolves/Mobile%20Uploads/IMAG1383_zpsjno7hc18.jpg

Update: No leaks, and works fine. I've noticed that when the rear arm is moved to the right, it stops on the button. But, when moving left, it takes a little more travel to stop, and you can clearly hear a cavitaing/fluid noise for a second before it comes to a halt. Not sure if its coming from the slew actuator or the lever block.

Any ideas on what I should be looking for. ?