Hewland LD200 cracked case. Repair?

[Roux]

My LD200 has this crack between the pinion bearing hole and the input bearing hole. I found the same crack in a spare case that I have laying around. Is this something that can been repaired successfully with welding? Or do I have a nice pair of doorstops?
thanks for any ideas

Steve

[Lee Johnson]

Steve ---

Try contacting Hewland Classics (they have provided me good info in the recent past):

http://www.hewlandclassic.com/contact.html

Or, on this side of the pond, try Scott Young (ex-Taylor Race Engineering):

https://www.sy-gearboxes.com/contact-us

Please provide updates to this thread on what you find out & what results are with whatever path you pursue. Share the knowledge with the community!

Lee

[Roux]

Lee,

thanks. I also found a Facebook Hewland page and applied to be accepted into the group to ask there as well. I see Scott Young is active there as well and I will give him a direct call as well

thanks

Steve

[tlracer]

The Hewland page on Facebook is run by Mark Bailey, a long-time specialist, and William Hewland - there are also a number of others on there with a massive amount of knowledge (Tony Wilson, Kevan McLurg for two...) so you should be in good hands with advice!

[CJD]

I would check Gear Daddies as well up in Wisconsin.

[ChristopherBernard]

I'd be curious to know why they crack there.
Stress riser in the casting on the inside?
Strange load path from suspension mounts ?

Chris

[problemchild]

Do you know that the crack is fresh? Could it have been there since a crash, decades ago. Perhaps once bolted altogether, the bolted in components provide enough integrity that the crack does not have an impact under normal use.

Almost anything can be welded if you have the ability to properly machine it afterwards.

Kevin at Comprent is the dealer for Elite transmissions which are clone Hewland LD200. While the quality of parts are debatable, that may be your best option to purchase a replacement case.

[Roux]

I'd be curious to know why they crack there.
Stress riser in the casting on the inside?
Strange load path from suspension mounts ?

Chris

Chris, there are two main events that might be involved.

One: Fatigue due to the force of the pinion pushing the diff in rotation but also constantly to drivers left via the bearings in the sideplate. The stress riser here is the series of three holes and the crack seems to have chosen the obvious path. This is a tension force (bearing preload) with a cycling ripple on top of it.

Scenario two and the more likely is the failure of the ring gear which then jammed hard into the sideplate, locking up the diff in the process. Lots of instant high force putting this area of the box in tension and then it unzips at the area with maximum stress

Scenario three is the combination of the above

Scenario four is none of the above.

[Rick Iverson]

I would check Gear Daddies as well up in Wisconsin.

Scott is good people.

The Gear Daddies, LLC.
20785 Junco Court
Lakeville, MN 55044
Direct: 952-201-5786
Fax: 952-469-0542
Email: scott@thegeardaddies.com

[EACIII]

Was the ring gear a recent event and why you took the case apart? If so I would lean to that being the cause.

Ed

[Roux]

Case pictured here; origin of issue unknown, but the sideplate has big scars. It is a spare case that I have and has never seen action in my car.

Second case with the identical crack was in the Wyvern at the ARRC in 2019 and on the long back straight I lost drive in 4th gear. Heavily light-weighted iron/steel diff had failed where the ring gear bolts to it and then the ring gear itself broke. Diff locked up, broke both drive shafts instantly and since they let go in synch with each other no sharp pull to either side. A good thing! since there is a lot of concrete to bash into if the car skewers to the right! The resulting damage caused by that diff lockup looks just like the damage to the sideplate in housing 1 which is pictured here.

I have a spare LD200 with a ratty ring and pinion, and that has been in the car ever since Nov 2019. It has been a champ for the past 12 races, but I wanted to demote it back to spare status by building up a primary box with a pristine R&P that I bought here in Apexspeed. I hope to find that case currently in the car to be in perfect shape. Fingers crossed.

Summary, my racing season is not lost unless I find something bad in the one that is in the car. I plan to take a look this weekend. Fear is that the diff or R&P is beat.

Steve