200 4R first gear slipping

[mred355]

Hi Guys. I just took my Regal out of storage and took a short run and noticed first gear was ok driving normally; but slips under a quick take off. The rest of the gears are fine under load and shifts are very firm. I did a pressure check and the pressures are normal for a modified trans. I bought it a few years ago and only have under 5,000 miles on it. Any help would be appreciated. Ed

 

[mikestertwo]

Does it slip in manual low?

 

[Nick Micale]

A trans guy here on the board directed me to this additive, and I have used it in many different vehicles, and in every case some improvement, to very good improvement of firmer shifts and less slippage.

For a car not used often, this is a great product!

https://www.amazon.com/gp/product/B002MB57UI/ref=oh_aui_detailpage_o09_s00?ie=UTF8&psc=1

 

[mred355]

Does it slip in manual low?

I didn't think to check manual low. We looked in the CK Performance rebuild book and it said to check the forward clutch. My Son pulled it today and we checked the forward clutch clearance with feeler gauges. It has .100" clearance. Could that cause the problem? If not what else would cause the problem if we did check it in manual low and it was ok? greatly appreciate the help. Thanx Ed

 

[mikestertwo]

I didn't think to check manual low. We looked in the CK Performance rebuild book and it said to check the forward clutch. My Son pulled it today and we checked the forward clutch clearance with feeler gauges. It has .100" clearance. Could that cause the problem? If not what else would cause the problem if we did check it in manual low and it was ok? greatly appreciate the help. Thanx Ed

If it was ok when you put it in manual low or greatly improved that would point towards the forward clutch since the pump pressure is increased when you are in manual low. Did you disassemble the forward clutch to see if the steels where hot spotted or the clutch disks looked burned? A clearance of .100" is a little big. Did you install the wave plate? If the problem isn't the forward clutch the only other possibility is the rear roller clutch not holding.

 

[Rafs-T-Type]

A trans guy here on the board directed me to this additive, and I have used it in many different vehicles, and in every case some improvement, to very good improvement of firmer shifts and less slippage.

For a car not used often, this is a great product!

https://www.amazon.com/gp/product/B002MB57UI/ref=oh_aui_detailpage_o09_s00?ie=UTF8&psc=1

Why don't you use a USA amazon link ya limey. - https://www.amazon.com/Lubegard-63010-Platinum-Universal-Protectant/dp/B002MB57UI

 

[mred355]

If it was ok when you put it in manual low or greatly improved that would point towards the forward clutch since the pump pressure is increased when you are in manual low. Did you disassemble the forward clutch to see if the steels where hot spotted or the clutch disks looked burned? A clearance of .100" is a little big. Did you install the wave plate? If the problem isn't the forward clutch the only other possibility is the rear roller clutch not holding.

If it was ok when you put it in manual low or greatly improved that would point towards the forward clutch since the pump pressure is increased when you are in manual low. Did you disassemble the forward clutch to see if the steels where hot spotted or the clutch disks looked burned? A clearance of .100" is a little big. Did you install the wave plate? If the problem isn't the forward clutch the only other possibility is the rear roller clutch not holding.

 

[mred355]

The sprag was fine. The only thing I could was the wavy plate being missing. The forward clutch is corrected now and I am putting it back together. Is there anything else to check while I am in there?

 

[blklt1z28]

If it was a "built" unit be careful bc some builders as a preference do not use a wave plate, instead they may run an extra steel.

 

[TexasT]

i am guessing you are air checking each of the pistons? I used two waves in there to absorb a harsh apply when pulling it into gear. are you using a larger boost valve and other pieces to get the pressures up? Is the pump, vanes and rings in good shape? Good clearance?

 

[mred355]

everything checks ok. And yes the trans is modified with all the good stuff. All I found was the .100 clearance in the forward clutch and a small aluminum chip that was in the boost valve. I was a job to get the valve out as they must have hit it too hard to install it and shredded the aluminum a little. That is now corrected too. Waiting on gaskets now to re assemble it and try it out.

 

[gunzandgearz]

A trans guy here on the board directed me to this additive, and I have used it in many different vehicles, and in every case some improvement, to very good improvement of firmer shifts and less slippage.

For a car not used often, this is a great product!

https://www.amazon.com/gp/product/B002MB57UI/ref=oh_aui_detailpage_o09_s00?ie=UTF8&psc=1

That was me nick and that is a great product,by the way long time no speak hope everything is well

 

[gunzandgearz]

everything checks ok. And yes the trans is modified with all the good stuff. All I found was the .100 clearance in the forward clutch and a small aluminum chip that was in the boost valve. I was a job to get the valve out as they must have hit it too hard to install it and shredded the aluminum a little. That is now corrected too. Waiting on gaskets now to re assemble it and try it out.

.100 is way too much needs to be more like.030-.050 I personally like it on the lower end of that spec for hi perf.builds.also the roller clutches can test ok on bench and not hold under load (torque).