Transmission problem

[My92SVX]

Hello everyone,
I just bought my first SVX. Bought her knowing that the transmission is bad. I would like some input. She slips a little when putting her into either reverse or forward. Have to give her a little gas for it to catch. Once she starts going she feels ok. However, I noticed she doesn't want to shift into 3rd gear. She shifts fine from 1st to 2nd.. Any input would be great. I don't know much about the mechanicals of the SVX. However, they sure are BEAUTIES. Only 70,815 miles on her. HELP!!

Carlos
Proud owner "92" Pearle White

[Manarius]

Think it's time for a rebuild or a replacement. Maybe a brake band adjustment. At least it doesn't shift into 3rd and then not move

[odepaj]

Would it be a brake band adjustment if i can drive the car when i put it into first gear on the selector but if i put it into 2,3, or D it will not grip at all, just flares. i get no engine braking at all unless its in 1 also. any help is appreciated, a quick response is also greatly appreciated as i dont know when the next time ill be able to check this is.




dustin

[oab_au]

Originally Posted by My92SVX

Hello everyone,
I just bought my first SVX. Bought her knowing that the transmission is bad. I would like some input. She slips a little when putting her into either reverse or forward. Have to give her a little gas for it to catch. Once she starts going she feels ok. However, I noticed she doesn't want to shift into 3rd gear. She shifts fine from 1st to 2nd.. Any input would be great. I don't know much about the mechanicals of the SVX. However, they sure are BEAUTIES. Only 70,815 miles on her. HELP!!

Carlos
Proud owner "92" Pearle White

If it will not shift into 3 or 4th, then it is the high clutch that is slipping. If it does engage 3/4th, but just won't just slips when engaging 1/R, then it may just be a blocked screen filter, in the transmission pan.
What does the ATF oil look like, clean, smell burnt?

Harvey.

[Earthworm]

Originally Posted by oab_au

If it will not shift into 3 or 4th, then it is the high clutch that is slipping. If it does engage 3/4th, but just won't just slips when engaging 1/R, then it may just be a blocked screen filter, in the transmission pan.
What does the ATF oil look like, clean, smell burnt?

Couldn't the 1/R issue also be the low/reverse brake?

[oab_au]

Originally Posted by odepaj

Would it be a brake band adjustment if i can drive the car when i put it into first gear on the selector but if i put it into 2,3, or D it will not grip at all, just flares. i get no engine braking at all unless its in 1 also. any help is appreciated, a quick response is also greatly appreciated as i dont know when the next time ill be able to check this is.




dustin

Hi Dustin, looks like the 1/2 one way clutch is slipping/not operating. This is used in the D position, and is replaced by the low/reverse clutch, when the level is in 1st position.

Can't think of any thing else, that would cause this. I reckon the box will have to come out.

Harvey.

[oab_au]

Originally Posted by Earthworm

Couldn't the 1/R issue also be the low/reverse brake?

Your learning Dave, if it was, there would be no reverse, no 1st position, and no engine braking. The slow to engage 1/R can be a faulty pump gasket, that was in some of the early models. But as he has to give it a bit of gas to go, the line pressure may be low due to the screen being blocked.

Harvey.

[odepaj]

Originally Posted by oab_au

Hi Dustin, looks like the 1/2 one way clutch is slipping/not operating. This is used in the D position, and is replaced by the low/reverse clutch, when the level is in 1st position.

Can't think of any thing else, that would cause this. I reckon the box will have to come out.

Harvey.

Does the one way clutch only operate when in D though? because even if i leave the selector in 2 it flares, i would think if the one way clutch only operated in D then putting the selector into 2 would work. And I thought the brake band is what made the 1/2 gear change? I tried getting the car up to speed while driving in 1 and then manually switching the selector to 2 hoping that way it would shift while not being put under load from the engine and then it would grab but still nothing happens, it just flares like its not grabbing. Sorry if it is obviously the 1/2 one way clutch, but id like to learn how the 4eat operates.



dustin

[oab_au]

Originally Posted by odepaj

Does the one way clutch only operate when in D though? because even if i leave the selector in 2 it flares, i would think if the one way clutch only operated in D then putting the selector into 2 would work. And I thought the brake band is what made the 1/2 gear change? I tried getting the car up to speed while driving in 1 and then manually switching the selector to 2 hoping that way it would shift while not being put under load from the engine and then it would grab but still nothing happens, it just flares like its not grabbing. Sorry if it is obviously the 1/2 one way clutch, but id like to learn how the 4eat operates.

dustin

Sorry for the delay in responding.
Autos use a freewheel in the rear of the trans so that the gear box can drive the tail shaft but the tail shaft can't drive the gearbox.
It is used to allow the change of rotational speed to occur, without the drive line jarring. When the band is applied to stop the front sun gear for 2nd, the ratio suddenly changes, the freewheel unlocks the drive line to prevent the tail shaft from driving the gearbox, thus preventing the shock.

This freewheel also prevents engine braking, on over run, it will also prevent reverse gear from driving the Tail shaft, as it turns the output shaft backwards. To allow reverse to work, we have the Low/Reverse clutch, which locks the freewheel to allow reverse and engine braking.

The power flow is different in 1st gear, in the D position, than it is in the 1st gear selected position. As the car will drive in 1st position but not in the D position, we can look at this area to see that is used it the 1st, but not in D.


Looking at the dia. you can see the freewheels are locked in the D position, but are not locked in the 1st position, as the Low/reverse clutch is applied. This points to the freewheel Sprage clutch not locking up in the D position.
Which Sprage is slipping is a guess. If it is the 1/2 then the car may engage 4th gear if it is run fast enough in 1st position, then the selector is put into D. If it is the 3/4 sprage it won't. But as the box has to come out to fix either, it does not matter.

Harvey.

[bwb3]

Out of nowhere I lost reverse today. First it slipped badly but moved, second time nothing but slipping. Forward gears seem fine, a hesitation into first but the others shift crisply. I'll start with dropping the pan tomorrow and check out the screen per Harvey's suggestion. It has 74L miles, no abuse.
Gene