The Museum by Samuel Premkumar

Spicer Model 44 Axles

Spicer supplied Model 44 front and rear axles to Willys. These axles were of Salisbury design – a Gear carrier with a central “pumpkin” and two hollow shafts pressed in on either side. These axles came in multiple final drive ratios – 4.27, 4.88, 5.38 and 5.88. A 3.73 ratio was introduced much later for fuel efficiency benefits.

Production – 1949 onwards and continues even now in modified versions (Model 25 front axle might have been used in the earliest models)
Plant(s) – Mazagaon, Ghatkopar, Kandivli and also procured from Dana Corporation

The front axle of a 4WD vehicle is of Salisbury design with a 8.5″ hypoid crown gear and a 1.5″ pinion offset. The axle was of ball yoke design with kingpin bearings and was of full-floating design. Full floating design had two wheel bearings on either side. The drive to the front wheels were through a cardan cross.

Factoid – The hub cap (1) doubled up as a measure of wheel bearing grease to be used while carrying out “Hub greasing” activity.

The rear axle was also of Salisbury design with a 8.5″ hypoid crown gear with a 1.5″ pinion offset. The axle was of semi-floating design with one wheel bearing on either side.

These axles are still being used, with modifications, to take care of higher loads as well as changes in the wheel track etc.

Spicer T18 Transfer Case

Spicer supplied T18 Transfer Case to Willys. This transfer case was of 2-speed design and had a high gear (1 : 1) and a low gear (2.46 : 1) ratio. These transfer cases were fitted on all 4WD versions of CJ2A, CJ3A, CJ3B, CJ4, CJ4A, Station Wagon, FC150, FC160, FC260, CJ500D, NC670. It is still getting manufactured at Mahindra plants and are fitted in 4WD versions of the Mahindra Pikup, Bolero Maxitruck, Bolero Camper as well as the Roxor in the US.

Production – 1949 and continuing till date
Plant(s) – Mazagaon, Ghatkopar, Kandivali

The T18 transfer case had a sliding spur gear low gear and a dog clutch to engage 4WD. The vehicle needs to come to a standstill for shifting. It also had a provision to fit a power take-off unit.

Sliding spur gear (18), 4WD Dog clutch (9) . Power Take-off unit can be coupled behind the input shaft (7)

Factoid – The interlock system in the transfer case does not allow the possibility of a 2WD Low mode. A small interlock plunger between the two shift rails inhibits this operation. However coffee estate owners in Coorg know how to get “2WD Low” without meddling with the transfer case.

The original design of the T18 transfer case remains same even today except the shifting patterns have changed. Original shifting pattern had 2-levers which then moved to a single lever U-Shift pattern and finally to a single lever straight line shift pattern.

The T90 Warner Gearbox

Warner Transmissions (now Borg-Warner) supplied T90 3-speed gearbox from 1945 onwards. These gearbox came in variants which had different gear ratios – T90A, T90C and T90J. The T90C was fitted in CJ2A, CJ3A, CJ3B, CJ4, Station Wagon, FC150 and T90J on the FC160, FC260, CJ4A, CJ500D, NC670 vehicles. These transmissions were in production till 1996.

Plant – Mazagaon, Ghatkopar, Kandivali
Production – 1949 to 1996
Model – T90 Gearbox

The T90 transmission had some very unique design elements like the sliding first gear with a spur gear wheel – the vehicle need to be brought to standstill to shift in to first gear.

The counter shaft of the T90 transmission had 88 “uncaged” needle rollers which acted as bearings. These 88 needle rollers were arranged in 4 sets of 22 needle rollers each. Assembling a T90 gearbox countershaft was a highly skilled job and was done by specially trained mechanics. A missed or misplaced needle roller can ruin the entire gearbox instantly. Watch the assembly of the needle rollers in the video here (7.55 min to 16:00 min)

T90 gearbox. Sliding spur gear (19) and the hollow counter shaft (35)

The “Hurricane” Engine

The Hurricane Engine was a mechanical upgrade to the famous Go-Devil Engine. This engine was used on all Civilian vehicles, post the war.

In India, this engine was fitted on to the CJ3B vehicles manufactured by Mahindra & Mahindra and was in production for almost half a century.

Specifications of the Hurricane Engine –

Type – Named as F4-134, the engine is of F-head construction. The exhaust valve is located in the cylinder block and the inlet valve is located in the cylinder head. By moving the inlet valve to the cylinder head, the inlet valve could be made bigger and hence the engine can breathe better leading to higher power output.
No. of Cylinders – 4
Capacity – 134.2 cu.in (2199 cc)
Power – 72 hp @4000 rpm
Torque – 114 lb-ft @ 2000 rpm
Compression ratio – 7.4 : 1 (Higher compression cylinder head, 7.8 : 1 ratio, is optional)

Inlet Valve (13) located in the cylinder Head.
Exhaust valve (12) located in the cylinder block

Camshaft (15) driving an inclined shaft with oil pump (16) at one end and spark distributor at the other end

The “Go-Devil” Engine

The Go-Devil Engine was the most famous engine in the Willys range which participated in World War II. More than half a million units did military duty across the world and was instrumental in the victory of USA.

In India, this engine was fitted on to the CJ2A and CJ3A vehicles manufactured by Mahindra & Mahindra.

Specifications of the Go-Devil Engine –

Type – Named as L4-134, the engine is of L-Head construction. Both the inlet and exhaust valves are located in the cylinder block. This construction results in less overall height of the engine leading to lower bonnet lines. However the air entering the engine and the exhaust gases leaving the engine has to twist and turn , leading to lower breathing & scavenging capability of the engine.
No. of Cylinders – 4
Capacity – 134.2 cu.in (2199 cc)
Power – 60 hp @4000 rpm
Torque – 105 lb-ft @2000 rpm
Compression ratio – 6.48 : 1 (Higher compression cylinder head, 7.1 : 1 ratio , is optional)

Note – The L4-134 engine was also made in a 6-cylinder version, aptly named as the “Lightning Engine“. This engine was not used in India.

The above information/images are extracted from Willys-Overland Data book, 1950 edition. The book was carefully preserved by another historian from Mahindra, Prasad Aphale.

Anatomy of a CJ 3B

The CJ 3B was the first mass produced Jeep in India by Mahindra & Mahindra Ltd. The CJ 3B was in production till the early 1990s. CJ means “Civilian Jeep” and was extensively used by Government departments, Military apart from common people.

Below is a restored version of a CJ3B, preserved at the Service Training Centre of Mahindra & Mahindra Ltd at Igatpuri (Maharastra-India).

Equipment List – CJ 3B

Willys F4-134 , 2 lit, Side Valve Engine(F-head)
3-Spring finger clutch – Auburn Pressure Plate with Borg & Beck Clutch plate.
Carter Downdraft carburetor.
Novi Vehicle Speed Governor (Fore-runner of today’s Cruise Control).
Warner T90C, 3-speed transmission.
Spicer T18 , 2-speed transfer case.
Spicer , Power Take-Off unit.
Spicer , Propeller shaft with Double Cardan cross.
Spicer Model 44/25, Salisbury type Front axle.
Spicer Model 44, Salisbury type Rear axle.
Ross Cam & Lever, Steering gear.
Bendix HNSS Brakes , Hydraulic, Single chamber master cylinder.
Parking brakes – Cable operated on Rear Propeller shaft.
Kelsey-Hayes , Wheel discs.
Semi-elliptical leaf spring suspension, Hotchkiss drive with Hydraulic double-acting shock absorber.
Auto-Lite , electrical equipment 12V.
Ladder frame chassis with K-Member.
Pintle Hook for Trailer towing.

The cut-section model of the CJ 3B was restored by a team of passionate Engineers from Mahindra’s Service department, led by the author and Shailendra Deshmukh. The physical restoration was carried out at the dealership worksop in Nashik, Jitendra Motors. The restoration was completed in the year 2010 and the restored model is on display at Mahindra’s Service Training Centre (MILE) in Igatpuri.

The day the restored version arrived at Service Training Centre. The author is first from left.

©Samuel Premkumar 2021

CJ 3B

Start of Production – 1953* (Production continued till early 1990s)
Plant(s) – Mazagaon, Ghatkopar, Kandivali.
Model – Willys CJ 3B

CJ 3B is the upgrade of the CJ 3A model with a new Petrol Engine. The famed “Hurricane Engine” is fitted in the CJ 3B model. Coded as F4-134, it is the F-head design of the “Go Devil” L-Head Engine. In the F-head design, the inlet valves moves to the top of the cylinder head.

The F-head design increases the overall height of the engine leading to redesign of the bonnet – seen as a higher bonnet line in the CJ 3B model.

CJ 3B is fitted with –

Unique Identifiers –

Higher Bonnet line
80″ wheel base
No airvents on the windshield
Ventilating windshield option – The windshield glass can be swiveled open slightly at the bottom.
2 wooden blocks on the bonnet for the entire windshield frame to swing open/fall forward and rest on the blocks.

A previous version of the CJ 3B with top mounted Wipers

©Samuel Premkumar 2021

CJ 3A

The upgrade to the previous CJ2A Jeeps.

Start of Production – 1950*
Plant – Mazagaon
Model – Willys CJ 3A

Fitted with –

2.2 Liter “Go Devil“ Petrol Engine
L-Head construction
Approx 80″ Wheelbase

Unique Identifiers –

Low Bonnet line
Single piece windshield
Wipers mounted below windshield
Fresh air vents in windshield

CJ 2A

The first of the Jeeps to be assembled by Mahindra in India.

Start of production – 1949

Plant – Mazagaon
Model – Willys CJ 2A

Fitted with –

2,2 Liter “Go Devil“ Petrol Engine
L-Head construction
Approx 80″ Wheelbase

With both valves , inlet and exhaust, located in the cylinder block, the overall height of the engine is reduced. This results in a lower bonnet line.

However, the efficient breathing by the engine is restricted as the air has to follow circuitous route before entering and exiting the cylinders.

Unique identifiers –

Low Bonnet Line
Split Windshield
Petrol tank below driver seat

The first CJ2A assembled in India by Mahindra

Mahindra and Mahindra

J C Mahindra

K C Mahindra

Ghulam Muhammed

Jagdish Chandra Mahindra (1892-1951) and his brother Kailash Chandra Mahindra (1894-1963) along with partner Malik Ghulam Muhammed (1895-1956) created Mahindra & Muhammed on 2nd October 1945 to deal in steel trading business.

Post partition, in 1947, Ghulam Muhammed left India to become the Finance Minister of newly formed Pakistan. The company was renamed as Mahindra & Mahindra in 1947.

Mahindra started importing, later assembling and then manufacturing Willys Jeeps in India. Today Mahindra has expanded in to the design and manufacture of Tractors, Utility vehicles, SUVs, Small commercial vehicles, Light commercial vehicles, Pickups, Heavy commercial vehicles as well as 3 Wheelers. They are also one of the early adopters of Electric Vehicle technology.

Apart from mobility sector, Mahindra has major presence in Information Technology, Real Estate, Hospitality and Financing sectors.

Evolution of Mahindra logo –

The millennium logo – The Road Ahead – From 2000 onwards