DAVID BROWN 990

MJ in the UK · Jul 7, 2018

Hi folks,as a follow up to Fridays rust picture of a DB 990. DB first introduced the six stud rear wheel on the Cropmaster tractor in 1947 and used it on their highest horsepower tractors right up to the first year of the 990 Selectomatic tractors in 1966. The 950 tractor also had six stud rear wheels ad did the 850 for 1960 only then they went onto eight stud rear wheels as did the 880 tractors. If you want to use a motor vehicle on the road in the UK you have to regester it and fit a number plate with letters and numbers issued by the licencing authorty, Up to 2001 the last two letters told you were the vehicle was first regesterd and the letter S was used in all Scottish regestions and thats why I new the rusty DB990 was first regesterd in Scotland. MJ

Oliver 500 Wa · Jul 7, 2018

Thanks for the follow up!

It seems odd to have the later 850s with 8 studs compared to the larger 990 with 6 studs. In my manufacturing/engineering background things like that got changed to address an issue. That a smaller tractor needed to go to 8 studs while the larger brother could still go with 6 is a bit of a head scratcher to me.

rrlund · Jul 7, 2018

Not only that,but the 8 stud rears after 1960 on the 850s. I don't think the Oliver 500s were 8 stud until late 62 or 63 were they? My 61 500 gas is 6 stud rear and 5 stud front.

JD Seller · Jul 7, 2018

The six both pattern is a larger bolt circle so it would not have had the same force on it as the eight bolt smaller one. Just thinking along the lines of leverage.

Oliver 500 Wa · Jul 7, 2018

The six both pattern is a larger bolt circle so it would not have had the same force on it as the eight bolt smaller one. Just thinking along the lines of leverage.

That would be a factor. There are other factors that could affect the need for fewer or greater number of studs. Thickness of the wheel center would be one of the bigger ones. With thinner material, you need additional points of restraint to prevent cracking around the holes. Lots of unknowns for sure.

Oliver 500 Wa · Jul 7, 2018

Not only that,but the 8 stud rears after 1960 on the 850s. I don't think the Oliver 500s were 8 stud until late 62 or 63 were they? My 61 500 gas is 6 stud rear and 5 stud front.

My parts book for tractors with s/n 101500 and higher shows 8 stud final drives. The parts drawing for the front axle shows 5 bolt hubs but the part number for the bolts says 12 required. How's that for being even more confusing?

According to Tractordata.com (not sure how accurate their info is) s/n 101500 would have been sometime mid 1962 production.

jamstra · Jul 7, 2018

JS would be first registered in the county of Ross and Cromarty! Jim

Traditional Farmer · Jul 7, 2018

I have a later model 990 very good tractor and easy on fuel.

rrlund · Jul 7, 2018

Mid 62 sounds right. I think production ended in April of 63.

RedMF40 · Jul 7, 2018

If you want to use a motor vehicle on the road in the UK you have to regester it and fit a number plate with letters and numbers issued by the licencing authorty, Up to 2001 the last two letters told you were the vehicle was first regesterd and the letter S was used in all Scottish regestions and thats why I new the rusty DB990 was first regesterd in Scotland. MJ[/quote]

Thank you. Where I live we share the road with tractors that could crush cars. They have no license plates. I'm ok with that but the odd thing is that regular vehicle owners are required to have some kind of minimum liability insurance. No insurance=No registration plates. If you cancel or stop ins for any reason, the insurance co immediately notifies our motor vehicles dept which then imposes heavy fines and demands that the plates be turned in. This policy varies from one state to another.

MJ in the UK · Jul 8, 2018

The eight stud rear wheels was the same as a lot of British tractors sutch as MF35, IH B250 B275 B414 and Fordson Dexta. My parts book dose not show a serial number break for the five and six stud front wheels. The thing is lads the TV comedy program Last Of The Summer Wine centres arround the town of Holmfirth not 2 miles from the David Brown factory. I was selling DB tractos from 1966 to 1972 and thy was allways changing and modifying tractors without informing us . MJ

Oliver 500 Wa · Jul 8, 2018

..... the TV comedy program Last Of The Summer Wine centres arround the town of Holmfirth not 2 miles from the David Brown factory.

My wife (from Ireland) watched that show on our local PBS station. She loves those British comedies.

I was selling DB tractos from 1966 to 1972 and thy was allways changing and modifying tractors without informing us . MJ

I saw a lot of that too when I worked at a machine shop that was making parts for Freeman balers and other hay machines back in the 70s and early 80s.

DAVID BROWN 990

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