Hi all,

We’ve completed a full gearbox rebuild on the 8F35. Initially, the car had a jolt when shifting from P to D or R — the jolt into D was moderate, but into R it was severe. The driving quality was also poor, with small jerks, delayed or missed gear changes, and other common issues associated with this transmission.

After the rebuild, adaptation, and software update, the car now drives perfectly — all gears engage correctly with no jerking. However, there is still a jolt when shifting from P to R and then into D.

If shifting directly from P to D, there is no issue, and the same applies when going from N to D. But when shifting from R to D, there is a significant jolt.

The P/N to R no issues.

Any ideas?

Torque converter, that's what causes the issue mainly.

Did you change it?

Honestly, Ford just build junk

Hi @DaveT70 , and everyone else who is going to read this topic,

No, we didn’t change the torque converter, as it seemed fine at first glance/inspection. We did replace the mechatronic unit (with one from a perfectly working car), as we initially thought that might be causing the issue, but it didn’t help. We suspected that a solenoid or valve in the original mechatronic unit might not be working properly.

We thought that if it shifts from P to R without any issues, it would indicate that the torque converter is good.

Anyway, we now have a new torque converter ready to be fitted.

Hi all,

New torque converter didn't help, like nothing changed. But we've put another new mechatronic and there is left only a small bump when moving in to D, no idea why the original mechatronic (serviced) was doing this problem. Anyway now solved.

Thanks