I've had the Sonnax/Tricum installed for about a month now and love it. Good firm shifts and not to harsh at low speeds. I was able to tow my camping trailer this weekend and have a shifting problem(compared to shifting before Sonnax install). When down shifting from O.D. to 3rd on hills, the RPM's would go up to 3000-3200 and stay there(aroung 55 mph). Before installing the Sonnax/Tricum kit, this was normal except after climbing immediately to 3000 rpm, the tranny would drop down to around 2500 rpm at speeds of 60-63 mph. These are hills and mountain passes that I am very familiar with and know how my PSD performs on these grades. I tried many times to get the rpm's to drop once the tranny hit 3rd without any luck. This doesn't seem normal to me, but I'm not sure because of the Sonnax kit. I always manually downshift out of OD for steeper grades and the tranny isn't slipping. Any Ideas /ubbthreads/images/graemlins/shrug.gif
Sonnax/Tranny or T/C:Help!!!
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Re: Sonnax/Tranny Question
Yeah, any advise from other members with the sonnax would be greatly appreciated. I am having some goofy things go on with my trans after I installed this mod. I did everything step by step and now having some weird shifting issues like Grizz350
Yeah, any advise from other members with the sonnax would be greatly appreciated. I am having some goofy things go on with my trans after I installed this mod. I did everything step by step and now having some weird shifting issues like Grizz350
Re: Sonnax/Tranny Question
I did the Sonnax/Tricum mods at the same time I did the major tranny cooler upgrades last month. I just came back from a 2200 mile trip to Dale Hollow Lake in TN towing a 14K fiver. Any time uphill driving brought the engine to 2000 RPM (60 mph), I dropped it out of OD. RPM's went up to 2500 and slowly climbed as I accelerated up the hill. I rarely saw 3000 RPM before shifting back into OD at the top of the hills. I can't offer any suggestion as to why yours shifts the way it does, but the shifting issue doesn't occur in my tranny with the same mod. Could it be a TC issue?
Dennis
I did the Sonnax/Tricum mods at the same time I did the major tranny cooler upgrades last month. I just came back from a 2200 mile trip to Dale Hollow Lake in TN towing a 14K fiver. Any time uphill driving brought the engine to 2000 RPM (60 mph), I dropped it out of OD. RPM's went up to 2500 and slowly climbed as I accelerated up the hill. I rarely saw 3000 RPM before shifting back into OD at the top of the hills. I can't offer any suggestion as to why yours shifts the way it does, but the shifting issue doesn't occur in my tranny with the same mod. Could it be a TC issue?
Dennis
Re: Sonnax/Tranny Question
I don't think so, no slipping or noises and the shifts are great. Just concerned about the OD down to 3rd shift, its a lot different than before the install. I know that rpm's have little to do with mph. I just want to make sure I'm not ruining my tranny. /ubbthreads/images/graemlins/eek.gif
I don't think so, no slipping or noises and the shifts are great. Just concerned about the OD down to 3rd shift, its a lot different than before the install. I know that rpm's have little to do with mph. I just want to make sure I'm not ruining my tranny. /ubbthreads/images/graemlins/eek.gif
Re: Sonnax/Tranny Question
My guess is your TC is coming unlocked in 3rd gear when under load, this is really common with 01 trucks and a recipie for transmission disaster, because tranny temps will get hot quick, not to mention high egts at the same time.
If you did not have the problem before it seems to me the pressure mods done by the sonnax/tricum have caused the truck to switch to a different tc locking strategy and now you have tc locking issues. A simple effective solution may be to install an automatic TC lock controller similar to the one SP Diesel sells and set it to lock up your converter at around 40mph and unlock at 35mph.
My guess is your TC is coming unlocked in 3rd gear when under load, this is really common with 01 trucks and a recipie for transmission disaster, because tranny temps will get hot quick, not to mention high egts at the same time.
If you did not have the problem before it seems to me the pressure mods done by the sonnax/tricum have caused the truck to switch to a different tc locking strategy and now you have tc locking issues. A simple effective solution may be to install an automatic TC lock controller similar to the one SP Diesel sells and set it to lock up your converter at around 40mph and unlock at 35mph.
Re: Sonnax/Tranny Question
Thanks for the advice PSDHokie, I definitely want to correct this right away. How has the SP Diesel auto T/C worked out so far. Is the T/C in the 01 not as good as other years and can anyone recommend a replacement T/C. What are the symptoms of T/C failure.
Thanks for the advice PSDHokie, I definitely want to correct this right away. How has the SP Diesel auto T/C worked out so far. Is the T/C in the 01 not as good as other years and can anyone recommend a replacement T/C. What are the symptoms of T/C failure.
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