First drive in Series III

[Tom Santoli]

I have finally gotten to drive the 1975 109 Series III I bought a few months ago and am surprised at a few things, maybe the following is typical?

The truck wanders quite a bit and is tough to keep in a lane sometimes.

The drivetrain makes a loud clunk when taking off, shifting and reversing.

The rear tire breaks loose when taking off at a turn.

The truck bucks and surges when traveling in second gear but not when accelerating through second to third.

I have a 1962 Unimog 404 that is tighter and more civilised (though slower); if this stuff is typical of Rovers than I won't go crazy tracking down the causes.

Thanks,

Tom

[adkrover]

I think you have a pretty typical vehicle that has gone without servicing for a long time.

Most of what you describe sounds pretty typical of a vehicle that's been neglected. None of it sounds very major so go through it and it should be fine.

If it wanders on the road, it's most likely that the steering has a lot of moving parts and if there are a few things coming loose, it adds up to a lot. You could have a few loose bolts on the steering box or transfer relay or even worn ball joints or steering knuckles. All very easy to fix if you can find the loose spots. Jack up the front end, tie the steering wheel from moving and get out and wiggle the tires and look for the play.

The clunk could just be a worn u-joint on the main driveshaft or worst case a loose mount. Crawl under and wiggle the drive shaft at the u-joints and look for play. They should be tight. If that's not it, put a jack under the rear of the gearbox and try to lift it. If not that, check the engine mounts.

Not sure on the spinning tire unless your just lead footed. Maybe drain and refill the rear diff and check the old oil for metal fleck. Could be something there but not hard to swap diffs if need be.

The sputtering is most likely just a cry for a tune up.

The Rover may have 100,000 miles on it of abuse and neglect while the 404 may have 20,000 miles with constant service from the Swiss Army.

If you get it sorted out, all those things should go away.

[greenmeanie]

A couple of things to add to the previous post.
1. Steering. Check that the steering box has had the lash taken out with the adjusting nut. You'll find it on the side of the box under the cover in the driver's side wheel arch. Back of the big jam nut and gently tighten the adjuster.

Also check tyres for abnormal wear indicating a tracking issue, jack each corner in turn and look for badly adjusted wheel bearings (they usually whine when worn) and finally check the swivel preload per the maual (This usually manifests itself as shimmy after hitting a bump)

If your truck has half decent tyres and well maintained steering it should not wander unduly.

2. The clunk in the driveline as described is backlash. In similar fashion to the steering jack her up turn the wheel and watch for things moving. Typical issues are worn drive flange splines, worn diff, Prop shaft UJ's, transfer case output shaft nut and gearbox output shaft end nut. There is an outside prossibility of it being the clutch release mechanism but that wouldn't affect accel and deccel.

As stated previously give the engine a tune up. With tha as a baseline you can then chase problems.

Cheers
Gregor

[I Leak Oil]

I have finally gotten to drive the 1975 109 Series III I bought a few months ago and am surprised at a few things, maybe the following is typical?

The rear tire breaks loose when taking off at a turn.

Tires breaking loose on a series truck? That's not typical! My 88" barely breaks the wheels loose in the mud it's so under powered!

I had a 109" with the HD rear springs that would do exactly what you describe as far as the wheel breaking loose. The springs were so stiff that the weight would come off the inside wheel causing it to spin.
Jason T.

[Terrys]

I agree with the other posters. Wandering can almost always be traced back to swivel ball preload or relay bushing wear. The wider the tires the worse it gets.

[msggunny]

Sounds like what the others have said, It needs some work for sure, but it doesnt sound like anything i would shy away from.

[JimCT]

Unimog

We have two Mogs and yes they ride like Mercedes, unless somepne has driven a Mog they would never believe how smooth they ride and how well they actually handle. But Series Rover really have heart. Jim

[SafeAirOne]

The truck wanders quite a bit and is tough to keep in a lane sometimes.

I quickly scanned the responses--hopefully I'm not echoing someone else...

There are 6 ball joints in the Series III steering system. If each one has 3/32" slop in it due to wear, the total slop at the farthest wheel will be a whopping 9/16" which would give you a sporty ride, to say the least. The good news is that it is easy to troubleshoot and (usually) cheap to fix, dependinging on where you source the parts.

With the truck on the ground, place a body part (knee, leg, foot, etc.) against one of the front wheels while an assistant gently rocks the steering wheel back and forth. Observe how much play there is in each link in the system before you can feel the wheel move. Don't forget the 2 ball joints between the steering box and steering relay. If the steering wheel moves a decent amount before the arm on the steering box moves, you may need to adjust the backlash on the steering box as others have recommended.

The drivetrain makes a loud clunk when taking off, shifting and reversing.

I concur with everyone else. Universal joints. Cheap and relatively easy to replace. Available at your local auto parts store.

The rear tire breaks loose when taking off at a turn.

I'm presuming that you have a 6-cylinder, have nothing at all in the back tub of the Rover and are on a dirt road (or there is a copious amount of sand on the pavement where you took off).

The truck bucks and surges when traveling in second gear but not when accelerating through second to third.

My '98 Nissan Sentra does this when I've got the engine idling (no gas pedal) in 2nd gear, like when I'm in very slow-moving traffic and am just sort of slowly coasting in 2nd. The idle RPM of the engine is just right to take up all the backlash in the driveline (including gearboxes) and push the car forward JUST ENOUGH to put all the slop back into the driveline. Then it does it all over again and again and again unless I downshift into first or add a little accelerator pedal to keep the engine above the "whiplash rpm".

I have a 1962 Unimog 404 that is tighter and more civilised (though slower)...

Those Germans and their obsession with precision and close-tolerences...It's an agricultural vehicle for Pete's sake! A proper one should be loose, noisy and should certainly wear the driver out after a few hours of continuous operation!