Transmission Mods

[svxwill]

why you drop QC from the list? it seen that's a good value mod and it's by OAB_AU

[Huskymaniac]

Originally Posted by svxwill

why you drop QC from the list? it seen that's a good value mod and it's by OAB_AU

Nothing personal intended toward OAB as he is a great source of information and help. When I researched it I found several people that were concerned about the bypassing of the torque control signal. I like the other aspects of the design but that scares me. If I were looking for performance, it would be a different story but my concern is exclusively for improving reliability. Not sure if I should have included the power mode switch mod. I was thinking that running higher RPMs and lower torque had some reliability benefit. Not sure if that is accurate.

There is also opinion that #5 may do as much damage as good. Again, I was thinking that a small resistance increase would increase line pressure slightly. But there are trade-offs.

[oab_au]

Originally Posted by Huskymaniac

Nothing personal intended toward OAB as he is a great source of information and help. When I researched it I found several people that were concerned about the bypassing of the torque control signal. I like the other aspects of the design but that scares me. If I were looking for performance, it would be a different story but my concern is exclusively for improving reliability. Not sure if I should have included the power mode switch mod. I was thinking that running higher RPMs and lower torque had some reliability benefit. Not sure if that is accurate.

There is also opinion that #5 may do as much damage as good. Again, I was thinking that a small resistance increase would increase line pressure slightly. But there are trade-offs.

Yes you might like to ask any of the 100 people that are using it, what they think.

Harvey.

[Huskymaniac]

Originally Posted by oab_au

Yes you might like to ask any of the 100 people that are using it, what they think.

Harvey.

I'm sure there are lots of people happy with it. I am just being cautious. This is my daily driver. That was probably a stupid choice but what's done is done. At this point my focus is doing things that I am sure will help reliability. Any doubts, even if misguided, will scare me away at this point. The only things everyone agreed on were the cooler change, the valve body change and frequent fluid changes. I even had one person tell me driving in "3" around town is not necessary. I don't drive fast around town so I do it anyways. I figure it couldn't hurt.

I got my first fluid change yesterday. The mechanic said the fluid looked and smelled good so I am cautiously optimistic. He only got 4 quarts out of it though. He had it flat on a lift. I will be going back at my next oil change and have him do a second drain and re-fill.

[svxwill]

good luck on long life for your trans.
my first svx had it rebulit 2 times and on 2nd time when i added the SmallCar kit with subaru external filter, which made it die faster (there wasn't as much info few years back). when i got the 92svx this year, i just changed the internal filter and put new oem atf. not sure i will do any mod to this trans.

[NeedForSpeed]

Originally Posted by Huskymaniac

At this point my focus is doing things that I am sure will help reliability. Any doubts, even if misguided, will scare me away at this point.

If the above statement is your only true objective, you should immediately delete your entire list. You can not be 'sure' of any of it. Items 1,3,5,6 are considered 'performance' mods, usually for those that drive accordingly. Items 2 and 4 are considered reliability/maintenance mods, but not everyone agrees on the cooler or on synthetic You clearly and correctly stated, the list is based on 'what people believe'.

To my knowledge, other than maintenance, none of the six items you listed has ever been proven to add reliability to a ’96 SVX transmission under normal road use. Most items on your final list have been tested sparely, and for relatively few miles, with mixed reviews.

You have taken the biggest step known and observed in increasing transmission reliability in an SVX, namely, driving a post-92 SVX. I believe that nearly everybody agrees on that. These later transmissions, when properly maintained according to Subaru, will easily approach 200,000 miles without failure. In fact, how many here have had a 96-97 transmission fail?

By 96, Subaru engineers had enough years and miles to correct early reliability concerns in the SVX. That is what you risk by making changes to a car you consider a 'daily driver'. I do not believe that any advice given here regarding reliability, other than periodic fluid change, is conclusive.

If you are looking to change the performance of your transmission, the 'safe' question is a different question entirely, with many opposing opinions.

[kwren]

I think Huskymaniac pretty much has it worked out... 16 hours every day, siting at the computer pursuing his quest to get extra life out of a transmission that actually quits working whenever it chooses... instead of driving the car around town...
Never taking it out for a fun drive but just letting it sit all the time while he sits at his computer and "researches" this, sounds like the answer to a long transmission life to me.

Keith

[Manarius]

Originally Posted by NeedForSpeed

If the above statement is your only true objective, you should immediately delete your entire list. You can not be 'sure' of any of it. Items 1,3,5,6 are considered 'performance' mods, usually for those that drive accordingly. Items 2 and 4 are considered reliability/maintenance mods, but not everyone agrees on the cooler or on synthetic You clearly and correctly stated, the list is based on 'what people believe'.

To my knowledge, other than maintenance, none of the six items you listed has ever been proven to add reliability to a ’96 SVX transmission under normal road use. Most items on your final list have been tested sparely, and for relatively few miles, with mixed reviews.

You have taken the biggest step known and observed in increasing transmission reliability in an SVX, namely, driving a post-92 SVX. I believe that nearly everybody agrees on that. These later transmissions, when properly maintained according to Subaru, will easily approach 200,000 miles without failure. In fact, how many here have had a 96-97 transmission fail?

By 96, Subaru engineers had enough years and miles to correct early reliability concerns in the SVX. That is what you risk by making changes to a car you consider a 'daily driver'. I do not believe that any advice given here regarding reliability, other than periodic fluid change, is conclusive.

If you are looking to change the performance of your transmission, the 'safe' question is a different question entirely, with many opposing opinions.

I think with the mid-94 to 97 transmissions, not driving like a race car driver is the best way to keep the transmission from breaking.

Also, I remember Trevor saying that driving in 3 was a good way to help. That's kept me with my stock tranny and 190k miles.

[Huskymaniac]

Originally Posted by NeedForSpeed

If the above statement is your only true objective, you should immediately delete your entire list. You can not be 'sure' of any of it. Items 1,3,5,6 are considered 'performance' mods, usually for those that drive accordingly. Items 2 and 4 are considered reliability/maintenance mods, but not everyone agrees on the cooler or on synthetic You clearly and correctly stated, the list is based on 'what people believe'.

To my knowledge, other than maintenance, none of the six items you listed has ever been proven to add reliability to a ’96 SVX transmission under normal road use. Most items on your final list have been tested sparely, and for relatively few miles, with mixed reviews.

You have taken the biggest step known and observed in increasing transmission reliability in an SVX, namely, driving a post-92 SVX. I believe that nearly everybody agrees on that. These later transmissions, when properly maintained according to Subaru, will easily approach 200,000 miles without failure. In fact, how many here have had a 96-97 transmission fail?

By 96, Subaru engineers had enough years and miles to correct early reliability concerns in the SVX. That is what you risk by making changes to a car you consider a 'daily driver'. I do not believe that any advice given here regarding reliability, other than periodic fluid change, is conclusive.

If you are looking to change the performance of your transmission, the 'safe' question is a different question entirely, with many opposing opinions.

OK, I will grant you that no one can be sure that any of them will work. However, items 1-4 have never been said to cause damage or possibly make the reliability decrease. But you are right in that, in every case, someone will argue that it doesn't help reliability. I guess I am putting up that list as items that have been widely claimed to be beneficial while not harmful. However, item #6 is the most debatable in terms of whether it will help at all. And item #5 is probably the item that will get the most claims as possibly causing more harm that good. In my mind, though, it does increase line pressure but not to the point where the original intent of that resistor is completely removed. Personally, I am planning to do items 1-4 over time.

On the cooler, there is some debate as to its necessity but it is widely believed that the improved FLOW is, in itself, a help for reliability. Whether the cooling capacity really helps is what is debatable. And whether either is needed for a later model SVX is also debatable I suppose. But I don't see how it could hurt with the only possible exception being that it can restrict air flow to the radiator if placed between the condenser and radiator or in front of the condenser. That can raise engine temperatures. Also, if the cooler is too big and the climate too cold, one might never lock up the torque converter and that will cause poor gas mileage. So, for my car, I am thinking of getting a smaller, lower flow resistance cooler. The estimate I came up with for the cooling capacity of the stock cooler was around 2000 GVM. Any cooling above that is a bonus but the main goals are low flow resistance and small size.

The folks at Hayden were kind enough to send me actual data on their Model 676 cooler. For the size, it is quite efficient at cooling and I can estimate the flow resistance from the data they gave me. I compared that with a flex-a-lite 4110 cooler. I calculated the flow resistance from equations for laminar flow. What I don't know is how turbulant the flow is and how much higher the actual flow resistance is. Flex-a-lite has not supplied data per my request. That alone makes me lean toward Hayden.

Here is a summary of the evaluation thus far:

[kwren]

Could we please get Trevor back??

Trevor had a way of enlightening folks that were completely out of the realm of reality in a way that they could understand

Keith