OJ Avery Posted July 12, 2018 Share Posted July 12, 2018 I have a 13 GU with a 3000/4000 series ( I think ) Allison in it. Serial # 6610336363, cooling system is full of trans fluid so my assumption is the cooler is bad. its an internal one on the back of the trans. I'm not finding much literature on it so any help would be greatly appreciated. Is it as straight forward as the parts diagram shows? Do's and don'ts ? Thanks!! Quote Link to comment Share on other sites More sharing options...
OJ Avery Posted July 13, 2018 Author Share Posted July 13, 2018 Hello??..is this thing on lol?? another question, I am having no luck finding any literature on this thing. I pulled the cooler and put it in the parts washer tank and put about 30# of air to it , no leaks. what is the typical pressure running through the cooler?? Quote Link to comment Share on other sites More sharing options...
Mackpro Posted July 14, 2018 Share Posted July 14, 2018 We have no dealings with anything Allison at our shop even though we sell quite at few new ones with Allison trans in them. We send them to our authorized Allison dealer 1 Quote Link to comment Share on other sites More sharing options...
BC Mack Posted July 15, 2018 Share Posted July 15, 2018 you won't get too many guys on here experienced on Allison trans, as said it is mostly a dealer thing.... I've worked on the B400/500 but in a bus application, not too different to what you have... we have laptops and trans dyno to use so I am not going to point out any bush repairs as failure is costly with an Allison... and they don't work for too long with antifreeze in the clutchplates so hope you got there early and nothing leaked back into the trans. buses have a remote cooler because the retarder mounts at the rear but similar in application to what you have, an oil core inside a coolant can..!!!! I assume yours is an oblong unit under the output flange??. it is probably the source of your problem, but we don't see too many of that fault just blocked up with debris or cracks causing coolant drips...we remove them on a semi-regular basis for reverse flushing and pressure testing if the oil core has a leak we scrap the whole unit, we just fix the can. pressure inside the trans is up to 300psi so we use Transynd not ATF literature would be generic and there are manuals on ebay and how to videos on youtube (try 'Allison 4000') you have to be an approved Allison shop to get the on-line manual and they are VERY specific to serial number, especially for parts pages, I made my own up for all our variants but never printed the cooler section, or pto..!!. we pressurise the coolant side to 100psi immersed in a water tank, the reverse flush is done on a machine with a air/hyd pump and pushes about 150psi through them....not sure how you would hook up the hydraulic side on your unit if you get totally stuck I get back to my old shop occasionally, books are there, but I think you need info quicker hope this helped BC Mack 1 Quote Link to comment Share on other sites More sharing options...
OJ Avery Posted July 16, 2018 Author Share Posted July 16, 2018 Thanks BC Mack and Mack Pro. I contemplated sending the cooler out for pressure testing because even though I didn't know what the pressure at the cooler typically was, I knew I wouldn't be able to simulate it. But I went with a new cooler. Second try of course. I ordered everything before I took it apart, I ordered a 7 plate and this has a 17 plate cooler. Yes the cooler is below the output shaft. We've started servicing the Allison's here, and typically anything more than that we send to a Allison dealer, but I figured this wasn't a complicated process so we decided to keep the truck here. We have a couple hundred 13-15 Mack GU with the Allison and we've experienced very few problems. Thanks again , I can always count on both of you to help out. Quote Link to comment Share on other sites More sharing options...
OJ Avery Posted July 25, 2018 Author Share Posted July 25, 2018 I'm having troubles locating Allison service bulletins, specifically Allison sil 18-TR-98 Any help would be appreciated Quote Link to comment Share on other sites More sharing options...
BC Mack Posted July 29, 2018 Share Posted July 29, 2018 On 7/25/2018 at 5:15 AM, OJ Avery said: I'm having troubles locating Allison service bulletins, specifically Allison sil 18-TR-98 Any help would be appreciated I'm on vacation right now, will try to dig it out when I get back, if we have access to that one... hope you're in no hurry BC Mack Quote Link to comment Share on other sites More sharing options...
BOB DINGSDALE Posted July 29, 2018 Share Posted July 29, 2018 to get oil in the cooling system you are getting trans pressure leak.you need to know what the trans pressure is. Quote Link to comment Share on other sites More sharing options...
BC Mack Posted August 5, 2018 Share Posted August 5, 2018 On 7/25/2018 at 5:15 AM, OJ Avery said: I'm having troubles locating Allison service bulletins, specifically Allison sil 18-TR-98 Any help would be appreciated Sooooo, I get back to the tranny shop and see #1 guy there.... he searches the database and nothing comes up.... so we did a word search of all our on-line manuals and find it as a reference for one of the assembly sections... but no 'go to' button..... the text refers to water or glycol check as I mentioned before, water or glycol is kryptonite to these trans as the bonding glue holding the friction surface to its disc is water based and as the debonding occurs the friction surface comes apart... end of tranny he's going to dig deeper and get back to me if he can find info, but his comments were to flush the trans, flush again, filters, filters, run with synthetic and do lots of samples... make sure there is NO water or glycol coming back on the oil reports. not sure what your change frequency but we used ATF changing at 24,000km, now we have gone to Transynd at 72,000km changes, samples at 24k.... with retarders we were boiling the oil on downhill runs, synthetic took the heat with no issues... now the coolant overheats and warps the engine block..!!! can't win with hills... BC Mack 1 Quote Link to comment Share on other sites More sharing options...
bbigrig Posted August 5, 2018 Share Posted August 5, 2018 (edited) Our newer Allison 4000 and 5000 series on Bus application (2015 and up) have the stack plate type trans coolers under the drive shaft. Plate type coolers always seem to have a higher failure rate. The old standard pressure testing both sides may not show signs of leakage. Your test won't produce heat which is a large cause of plate type cooler failure. It's the only spot your coolant and auto trans fluid mix. Change it and flush both systems real good. Edited August 5, 2018 by bbigrig 1 Quote Link to comment Share on other sites More sharing options...
OJ Avery Posted August 20, 2018 Author Share Posted August 20, 2018 So everything seemed to go well until last week. I heard from the residency mechanic that when its got a full load it shifts hard 1-2 and there's a code for a solenoid. Haven't seen the truck yet, will keep you updated. Thanks for all your efforts, I appreciate you all!! Quote Link to comment Share on other sites More sharing options...
BC Mack Posted August 21, 2018 Share Posted August 21, 2018 12 hours ago, OJ Avery said: So everything seemed to go well until last week. I heard from the residency mechanic that when its got a full load it shifts hard 1-2 and there's a code for a solenoid. Haven't seen the truck yet, will keep you updated. Thanks for all your efforts, I appreciate you all!! don't panic yet..!!!!! depending on mileage (ours are toast at 350km of city work) it could be simply a piece of debris stuck in the valve body.... N-D-N-R a few times on the keypad when at idle may be all it needs.... it's one of the most common complaints we get.... check the code and the manual will run you through the problem, pressure checks etc, if you have to drop the pan that will expose the valve body and solenoids, if you have to remove any wiring be careful with the clips on the solenoids as they get brittle with the heat and the wiring can also 'snap'... BC Mack 1 Quote Link to comment Share on other sites More sharing options...
Frank 2002 holiday rambler Posted January 21, 2021 Share Posted January 21, 2021 I have a 2002 Holiday Rambler diesel pusher that had the rear mounted radiator crack internally and while running push ATf into the antifreeze. Then upon shutting it down push antifreeze into the trans..... I am looking for a dedicated trans oil cooler to hang behind the existing rear radiator . I plan to flush that radiator and plug the transmission fluid side. I need help finding the right replacement... I can fabricate a mount as needed... The piping thru the existing trans system is 3/4 fip Quote Link to comment Share on other sites More sharing options...
Frank 2002 holiday rambler Posted January 21, 2021 Share Posted January 21, 2021 It's a roadmaster 3200 chassis 6 speed allison 3000 series trans Quote Link to comment Share on other sites More sharing options...
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