[sportylemans]

Hi everybody, been a while. Got my 71 lemans, 350/th350 together, running and painted. Having an issue with the trans. Shifts good into drive, neutral and low. Reverse is really hard shifting. With the hood up, I can see to engine move up on the passenger side.

Thought it might be the motor mount so I used a crowbar to check. Was able to lift the passenger side about 1/2 inch. Replace the passenger side mount and still does the same thing.
Also checked
1. Vacuum source, getting 17 on the gauge manifold vacuum
2. Idle set to 725, in gear goes to 625
3. Checked modulator and hoses.
4. Timing at 12btdc w summit 2800 cam
5. Changed both u joints

Runs great, shifts great while driving, just shifting in reverse feels like the engine is going to rip out.

Tranny was rebuilt 7 years ago and a trans go shift kit installed. Under 10k on it. Working great until a couple weeks ago.

I'm running out of things to check. Are the motor mounts supposed to have any play in them? Any ideas on what to look at next?

[torqjunki]

Subscribing....my fresh T400 does that as well. I pull it into drive and then to reverse to keep it from hitting hard.

[sportylemans]

Thanks, tried that and still really hard shifts. Wondering how much play should be in motor mount frame bracket and the mount. Can lift it about 1/4-1/2 inch. Unless the shift into gear is just to much for it. Also wonder if it could be high pressure in the low/reverse pack or the valve body?

[chiphead]

Reverse in a TH350 uses the Low/Rev and Direct (3rd gear) clutch packs. If the waved apply spacer has been removed from the Direct, it will hit hard as it shifts into reverse. The waved apply spacer softens the apply in stock trannies, but takes up space in the clutch pack and can hurt clutch pack life in high HP applications.

Now if it just started doing this, I would check for R&P backlash, tranny slip yoke spline/bushing wear, tranny mount and then internal to tranny. Could be sun shell wear, low/rev sprag or a few other parts inside tranny. But usually the tranny should be making noise or showing other issues soon after shift quality issues show up.

[sportylemans]

I think I eliminated the motor mount. I strapped that side of the engine down to the frame. Tried shifting it and the motor didn't move, but the shift was still really bad from park to reverse and neutral to reverse.

Chiphead, checked the tranny mount and it's good, tranny yoke spline is good as well. The waved spacer is in there, so looks like the tranny may need to be opened up. Probably start by checking the torque on the valve body bolts while draining it.

I think I can rule out the vacuum modulator since it shifts fine through th drive gears.

[SMW]

Check for sticking valves in the valve body. the direct and low/revers need to apply almost simultaneously. the clutches are applied by fluid pressure, if there is too much pressure the clutches will apply harder.