BritishV8 Forum

General Category => Engine, Transmission, & Rear Axle assy. => Topic started by: waterbucket on January 18, 2026, 05:35:46 AM

Title: Largest diameter propshaft without clearance problems.
Post by: waterbucket on January 18, 2026, 05:35:46 AM
Just as the title says, what is the largest diameter propshaft without clearance issues. The reason for the question is that I can get a used propshaft from a Reliant Scimitar with the MGC ends and get it shortened for a quarter of the price of an all new one.
Title: Re: Largest diameter propshaft without clearance problems.
Post by: mgb260 on January 18, 2026, 11:04:31 AM
Phill, My guess would be 2 1/2" and then you may have to shorten the Ebrake bolt. Have you seen the Speedway Fast shafts? 2" diameter.

https://www.speedwaymotors.com/Fast-Shafts-Steel-Drive-Shaft,49438.html
Title: Re: Largest diameter propshaft without clearance problems.
Post by: MGBV8 on January 18, 2026, 12:53:43 PM
Quote from: mgb260 on January 18, 2026, 11:04:31 AMPhill, My guess would be 2 1/2" and then you may have to shorten the Ebrake bolt.

I have a 2 1/2 inch diameter Camaro driveshaft.  It would ping the parking brake bolt when the rear suspension compressed.  Changed the nut to a thinner jam nut & cut the bolt flush. Been that way for just over 24 years.
Title: Re: Largest diameter propshaft without clearance problems.
Post by: waterbucket on January 18, 2026, 03:45:21 PM
Thank you both for the replies, I can get a used Reliant Scimitar GTE propshaft for less than a fifth of the cost of a new one. I think it comes with a Jaguar/MGC flange at one end, if the tube fits then just to get a RX8 UJ at the other end.
The problem with buying from the US is the tax and duty on arrival and sometimes a brokerage fee as well. I know that you now face the same when buying from the UK but it still hurts. Rockauto do a good job of shipping but sadly Summit and Speedway don't.
Title: Re: Largest diameter propshaft without clearance problems.
Post by: BlownMGB-V8 on January 19, 2026, 11:07:16 AM
Yes, as I recall we avoid the VAT with goods coming this way but that may have changed or may be applied unevenly. I suspect it would be to everyone's benefit to do away with the Tariffs on both sides.

Jim
Title: Re: Largest diameter propshaft without clearance problems.
Post by: Motorhead on March 25, 2026, 03:57:04 PM
Quote from: mgb260 on January 18, 2026, 11:04:31 AMPhill, My guess would be 2 1/2" and then you may have to shorten the Ebrake bolt. Have you seen the Speedway Fast shafts? 2" diameter.

https://www.speedwaymotors.com/Fast-Shafts-Steel-Drive-Shaft,49438.html

I have a Duratec 2.3L from a Ford Ranger in my 1974 MGB-GT.  Do you think the torque from this engine would be too much for the 2" diameter fast shaft from Speedway Motors?
Title: Re: Largest diameter propshaft without clearance problems.
Post by: mgb260 on March 25, 2026, 04:10:43 PM
No, racecars have used it with V8's.