Full steam ahead for traction engine after Loctite repair

An association of enthusiasts looking after a historic traction engine built in 1884 turned to the proven performance of Loctite products from Henkel to overcome the challenge of a worn steering shaft/worm wheel.

This heavy engineering task was no problem for Loctite 638 retaining compound, which filled the clearance created by wear, helping the engine to attend a recent vintage festival in Leicestershire. The engine will now go on to participate in a number of important fundraising events this year.

Traction engines are steam-powered tractors (sometimes known as agricultural locomotives) that were primarily employed to plough ground, move heavy loads on roads or provide power at a chosen location. Traction engines revolutionised agriculture and road haulage at a time when the only alternative was the horse. Production of these engines continued well into the early part of the 20th century, when competition from tractors with internal combustion engines saw them fall out of favour. However, several thousand examples have been preserved worldwide, many in working order.

One of these is Aveling and Porter traction engine number 1995 (registration BT 3939), which is owned and maintained by the eight members of the appropriately named 1995 Association (currently on the cusp of achieving charitable status). Among the membership is retiree Peter Hodgkinson, who has a 50-year association with traction engines, including a long spell heading up the R&D department at Aveling-Barford, which took over Aveling and Porter in 1933 after the company entered receivership.

“Aveling and Porter No. 1995 is a general purpose, single-cylinder, 6HP engine,” he explains. “We completed our second engine rebuild about five years ago, but like all traction engines manufactured in the 19th century, maintenance and repair tasks are fairly regular.”

A common problem across many types of shaft/gear assemblies is keyway backlash. With traction engines, the frequent number of starts, stops and load reversals can increase wear between the keyway and key, as well as in the slot and bore of the mating gear. The 1995 Association was experiencing this very problem on the steering shaft of its traction engine. A large worm wheel mounts to a 90mm long, 50mm diameter machined shoulder at the end of the steering shaft. The shaft and gear feature a 14mm wide key/keyway. Due to wear, there was a clearance gap of around 0.5mm (at certain points) between the shaft and worm wheel.

“The worm wheel on the steering shaft had worn quite badly, while the key had also worn and one of the locking screws had broken,” explains Hodgkinson. “Normally we would have the shaft metal sprayed and re-machined, but we had a number of important upcoming events that we didn’t want to miss, including fundraising events in Herefordshire where the engine spent much of its working life. To save time, I thought of trying Loctite, which I’d used for many decades in my various engineering roles. At Aveling-Barford, if ever there was ever a problem, Loctite often came to the rescue.”

Loctite products have long provided solutions for the repair of shaft-mounted components such as gear wheels and pulleys. These advanced solutions can repair worn keys, stop key and keyway wear, and protect new and reclaimed components against wear, abrasion and chemical attack.

To fill the clearance gap between the shaft and gear wheel on the traction engine, Henkel recommended Loctite 638, a high-strength, fast-curing retaining compound.

Firstly, all the parts were cleaned using Loctite 7063 general purpose parts cleaner. Loctite 638 was then applied into the keyway slot before putting the key in place. Loctite 638 was subsequently applied over the key and shaft, while a small quantity was also added to the bore of the worm wheel. This strategy provided good coverage before sliding the gear into position.

“We were all really pleased - the repair went as planned and the backlash has now gone as the Loctite compensated for ovality in the bore of the gear wheel,” concludes Hodgkinson.

This successful outcome meant the traction engine could attend its first event of 2022, the Great Central Railway’s Easter Vintage Festival at Quorn in Leicestershire.