Volvo 144 - BW35 Transmission Noise?
 

Had my '72 144DL out for a drive yesterday and I heard what sounds like a metallic clattering/scratching noise when accelerating from stationary or low speed just for a few seconds and then fades away. Its not very loud, but me being a car hypochondriac am concerned about it. Its definitely a rotating type sound from underneath, either from the transmission or from the driveshaft.

The car is changing up from 1 to 2 to 3 smooth but noticeable... do get the odd hollow 'clunk' noise sometimes when slowing down to turn left or right at a junction without stopping.


The trans fluid level is okay and clean, I keep an eye on that as it has a tendency to leak out some on the garage floor if the car left sitting for a few weeks and I keep it topped up with Comma AQF. I have no idea if the trans had been overhauled in its 147k mile history but there was 1/2 bottle of Valvoline DEX/MERC in the boot when I got her and the previous owner topped it up with, who was non the wiser.

Has anyone any experience of going down the easiest cheapest option and using automatic transmission fluid additive such as Wynn's Stop Leak/Conditioner or Lucas Transmission Fix which claim to stop leaks and do all sorts of magic?

I'll leave it to others to advise on recommended fluids etc, but I had clunking under mine years ago, and it was the UJs on the propshaft. The needles were dropping out as I touched it, so I limped home........
Love the chrome-plated number-plate light unit - new or just not faded yet?

P

Its a Hella unit, I don't know if it is the original as the car was restored some 20+ years ago.

If the car hasn't been out for a while, perhaps due to lock down, the scratchy noise might be rusty brakes. Worth a check. BW35 not the smoothest of auto boxes and thumps aren't unknown. Torque converter might have drained down a bit(?) and some energetic driving might sort the fluid out. Make sure you're checking the level by the book. Kick down cable adjustment? Worn out nylon bushings, or gone altogether, in the selector linkage at the side of the box?
Check prop shaft and central bearing support rubber as mentioned.

Well it turned out the that scratching/squealing noise I had was a bad rear universal joint, which had all but disintegrated. Replaced both the front and rear, centre bearing which all had some play. The centre UJ seemed okay, so left it be.

On test drive about 7 miles from home, it threw the new rear UJ cap. Managed to limp home and back on the jacks for inspection. I couldn't believe I had installed the rear shaft 90 degrees out of phase... when I had checked it, checked and double checked it... I also think the circlip may not have been seated properly as the yoke looked a bit battered.

Ordered 2 more UJ's from Brookhouse (1 spare just in case). Put a tiny dab of JB weld on the criclips for good measure and has seen 700 miles without issue.

Next job to tackle is the rough idle combined with fluttering vacuum gauge needle which has been like that since I got the car. I am hoping its just a head gasket failure between cylinders (previous owner confessed to it overheating it) but I wont know until I pull off the head. There is no oil in the water or water in the oil or loss of coolant. The head was overhauled with new valves, springs, guides @ 12k miles ago... in 1983.