Gearbox leak - Planning for a gearbox and engine pull

Post by: **2cams70** » Sun Aug 04, 2019 1:32 pm

135mm centre of U/J cup location to end of sleeve is the same as Cortina
I measured with vernier caliper internally approximately 115mm from end of sleeve to the internal end cap for Cortina. I think you measured 108mm but it's not clear for me from your drawing what your end reference point was.

Post by: **SENC** » Sun Aug 04, 2019 7:49 pm

I was measuring externally, to the neck where the machined section meets the yoke - the part that would "bottom out" on the tailshaft extension.

Internally measured as you did, my elan original is also 115mm - the internal measurement on the repro was a hair under 110mm.

: original and repro yokes

Post by: **2cams70** » Mon Aug 05, 2019 12:39 pm

Confirmed the original Cortina yoke measures 103mm externally from sleeve end to the face of the U/J housing. It therefore seems to be exactly the same as the original Elan one.

Post by: **SENC** » Mon Aug 05, 2019 9:56 pm

2cams70 wrote:Confirmed the original Cortina yoke measures 103mm externally from sleeve end to the face of the U/J housing. It therefore seems to be exactly the same as the original Elan one.

Haven't been able to find it, yet - do you by chance know the ford part number for the cortina slip yoke?

Post by: **2cams70** » Tue Aug 06, 2019 2:26 am

Part number is 69BB-4841 A2A
Hmm...surprisingly hard to find.
Your best bet is probably to source a second hand complete Cortina propshaft for parts.

Maybe this supplier could also help?? Their repro. yoke seems to be sourced from a different supplier to yours. You could always send them a note requesting dimensions in any case.

http://teamdeville.co.uk/product/prop-s ... 00e-box-2/

Post by: **vxah** » Tue Aug 06, 2019 12:19 pm

Try these people, they do/did donuts as well.

http://baileymorris.co.uk/

Post by: **SENC** » Fri Aug 16, 2019 1:48 am

A new TTR propshaft and yoke arrived today, only 2 days in transit - amazing!

As you'll see in the pictures below, the TTR yoke is different from the Kelvedon yoke, but essentially the same dimensionally - so would have presented the same problem on a standard propshaft. As you'll also see, the TTR propshaft has been shortened. The result is that the combined length from the diff flange to the base of the machined section is identical to the original, but giving up about a quarter inch (10mm) in length from flange to tip of the machined section, which is less important. This should perform like the original, without the increased risk of bottoming on the shoulder or on the welch plug that comes with the Kelvedon repro, which is equal in total length to the original but longer in flange to base of the machined section.

: Original vs TTR repro propshaft and yoke

: Original vs Kelvedon repro propshaft and yoke

Post by: **2cams70** » Fri Aug 16, 2019 5:50 am

Conspiracy theory here - yoke may be like that to force you to buy a complete shaft rather than just new U/J's and yoke to fully rebuild the old one. Are the U/J' larger than original? If so then it's a design improvement but if not it may be just conspiracy theory at work!

Post by: **SENC** » Fri Aug 16, 2019 12:49 pm

Ha! No, it appears the UJs are original size. But you can take off the tin foil cap, I think. From what I can tell after multiple emails to the main lotus vendors, if they carry a repro yoke it is of similar non-original dimensions to these from Kelvedon and TTR. TTR, however, appear to be the only ones that have come up with a solution, in this case to shorten the propshaft.

Kelvedon do acknowledge the problem and say they are working with their fabricator on a solution. I do not know whether that is a redesigned yoke or a shortened propshaft.

Post by: **SENC** » Mon Sep 02, 2019 2:25 am

Gearbox, bellhousing, clutch release bearing and arm back together, now awaiting being reunited with the engine and then back in the Elan. Was planning a long workday tomorrow, but looking like I'll need to focus on prep for Dorian instead.

: Gearbox after renewal

: Gearbox after renewal 2

Post by: **The Veg** » Mon Sep 02, 2019 10:54 am

Looks good. Stay dry!

Post by: **alan.barker** » Mon Sep 02, 2019 12:47 pm

I hope you remembered to seal the bottom left bolt that holds bellhousing to gearbox :mrgreen:

Alan

Post by: **SENC** » Mon Sep 02, 2019 2:07 pm

alan.barker wrote:I hope you remembered to seal the bottom left bolt that holds bellhousing to gearbox
Alan

Shockingly, I did!

Post by: **SENC** » Thu Sep 05, 2019 10:55 pm

Got a little done today while waiting on Dorian - ready for re-entry, I think.

Post by: **SENC** » Sat Sep 07, 2019 11:29 pm

Not sure how Buckland does it with the clutch slave cylinder in place. I struggled with the bell house jam for about an hour before finally taking the slave back out, then it was quite simple. Engine and gearbox back in, if I can find time tomorrow will start hooking it back up.