knocking noise in reverse (and other issues)

Hello

I am in the process of getting an old SIII on the road again, after it has been sitting for nearly 10 years. Overall it seems to be in fine shape, but there are a few issues that irritate me, and I would like to hear your opinion about them. I am throwing in everything I have observed since I am not sure which of these issues are related to each other.

The car is a 1974 S3 109 station wagon with a 6-cyl petrol engine, nominally seating 12 persons. It was originally used as a fire truck in a mountain village in Switzerland, and it appears that it is some sort of heavy-duty mod since some of the components are not standard 109 (for all I can tell - for example, the front brakes are 3” wide).

I have replaced nearly the entire brake system (master cylinder, all brake shoes, brake cylinders, and some of the pipes), and that works fine now (was hell to get all the air out of the system!).

Transmission brake shoes are new.
Clutch master and slave cylinders are both new.
All fluids changed (but see below).
New spark plugs and distributor cap.


I can drive and switch gears OK’ish, but I have the following symptoms:

• Some times when switching to reverse there is a scratching sound - my understanding is that there is no synchro for reverse, so this does not bother me too much
• When reversing, there is a knocking sound coming from the gearbox/transfer box. When I look at it I see that the transmission brake does a funny hopping motion - it is stuck for a bit and then does a partial turn before being stuck again. Loosening the brake shoes to the maximum does not change that.
• When forwarding in first gear there is a hissing sound at low speed that goes away after a bit.
• When driving downhill in first gear (using the engine brake) there are strong “hits” on the gear stick, and eventually it jumps out of gear. Appears to happen only in first gear (I presume because that is when the forces on the gearbox (?) are the strongest.
• When I filled the gearbox oil I could only add about 0.8 liters vs the 1.5 from the manual. Have not yet tried to top that up after driving a bit (but also did not drive more than a couple 100 m since then)
• The speedo does not work properly and jumps all over the place (my suspicion is a worn speedo gear, independent of the rest?)
• I can accelerate OK, but so far have only reached a maximum speed of around 80 km/h. When driving uphill I need to go to 3rd or even 2nd gear, 4th is way too weak. Not sure if this is the engine or transmission - I get no suspicious smoke (for all I can tell), but stinky exhaust, and occasional backfires.

For the last point I was thinking that my transfer box is stuck in low range, but I know I dont have 4wd engaged (jacking a single front wheel and turning it easily). Still have to check if the noise persists when in low range or 4wd/high range.

Steering and parallel parking kills my arms, but I guess that is something I should get used to

Cheers, and thanks for any help/comment! (unless the suggestion is to trash the car, but I am confident that on this forum this is the only suggestion I will not get )

Problems sound transfer box related, knackered bearings for example

The reverse jumping / banging - have you checked the engine / gearbox mounts are not knackered. Mine reversed like the back wheels were oval and new mounts transformed it. 1st gear Judder stopped too.
Power and speed wise, I think you'll find that's normal - so much less power compared to modern vehicles and even other models of that era.

X1 your power and speed observations are quite normal for a series landy, especially a 109. Your model is quite rare these days. The 6 cylinder engine is really smooth but look after it. The heads can warp easily. It's common for older gearboxs to jump out in 1st gear it's wear and tear. Be careful engine braking too much the engine will not like that. On steep descent just keep it in top gear and brake at a modest speed. Any photos?

Thanks for your replies!
John - good to know that engine brake is not liked by these engines. I am so used to doing it (and driving in the Swiss alps it comes in handy quite often...), but I will refrain from applying the same to the S3. Photos will follow
Raver - the mounts are good tip, I will check that when I get a chance. The engine mounts look OK, but I have not checked the gearbox mounts. I think I would prefer that to be the issue than something inside the transfer box.
So, naive question: can the transfer box be checked/repaired without removing it from the vehicle completely? I believe I would be able to repair a transfer box in theory, but I don't have a real workshop, so anything that can be in/on/under the car is easily doable, anything else is complicated.

I am also relieved to hear that the power issue is normal. I knew I was not getting a sports car, but given that the only car of that generation I have owned previously was a Mercedes I have a hard time judging what is normal about this car and what points to a problem. The fact that my model is rare makes it quite hard to find (to identify, actually) spare parts. Even the people at the usual online LR-parts retailers seem to be confused my the the model I have (but that may also be my fault...)! Some things also don't seem to be available anymore at reasonable prices - unfortunately I don't have the second row seats, for example, and thus far have failed at finding someone who offers them at less than 2000 currency units. So if anyone here knows of someone who does, in fact, offer those seats I would be delighted to hear about it!

A really good supplier of body panels and fixings are UK based YRM Solutions. Check their website.

i wish i had kept my 109 1968 safari 2.6, worth a few bob now!!

The 2.6 lumps are smooth however lathargic when compared to modern landys.

I would rebuild the transfer box and the gearbox just as a precaution
sitting doesn't do them any favours

Took her for a spin today, first time really since I have her - but I am under a bit of pressure since I have to pass the equivalent of the MOT here in Switzerland on Monday. But from what I understand they are somewhat more severe here, and the test is compulsory...
Either way, it is fantastic to drive this car! I know I dont need to tell this to anyone here, but for me it was new.
She drove fine overall, but still no power in 3rd and 4th - the slightest bit uphill and I can not go any faster than 40-50 km/h. Occasionally when driving slowly in low gear there is a hissing/scratching sound, as if a rotating piece was touching something. It is rhythmic and gets faster when I accelerate, and stops when I switch to 3rd gear.
Also, regarding my initial question about reverse (title of the thread): the knocking is there only when I dont press the clutch. If the car rolls backwards, everything is fine. My interpretation would be that this then can not be the transfer box nor gearbox (since both these are still connected to the wheels) but must be something else.

Photos - one from how I bought her (the kids I had before, they did not come with the car ) and two from today. I painted her myself, and the plan is to also paint the roof in limestone.

If it was at a fire station and has 3" wide brake shoes most likely a 1 ton landrover , which has a lower ratio transfer box / or different gearing they are very rare.
http://www.onetonlandrover.co.uk/development.html

Interesting suggestion, Blackburn. I did wonder about that for a moment while hunting for brakes, but then decided that it was unlikely to be a true 1-ton, given that it is a station wagon (did they build 1-ton station wagons?), and given the chassis number that starts with 949 (LHD 1-ton would be 269).
So my guess is that they modified the brakes. Possibly they also changed the gearbox...

Also, it was not really a firetruck but a transporter for personnel, I assume. When I got it, the shadow from the original emblem (name and flag of the village, plus "Feuerwehr"). It is registered as a 12-seater with explicit permission to have 6 people sit in the "trunk" - but (as I wrote above) the second row seats are missing.

I read that it's very important to frequently set the tappets on the 6cyl engines but I think they at least one of them is a challenge to get to. Might help with performance a little

I will keep that in mind, Land Raver. Even though I am already getting used to the weak performance uphill. I am discovering the beauty of slow driving...
The good news of today is that I passed the Swiss version of the MOT today, with a few minor things to correct/repair. So I can happily drive now without being bothered for two years. Unfortunately Swiss laws don't allow me to use the seats in the back anymore, and since I dont have the second row bench installed at the moment, my 109 station wagon has officially become a 3-seater!