4r70w transmission will snap your neck!
#1
4r70w transmission will snap your neck!
Hello all.
I have a 1994 F-150 2WD, 302ci/4r70w OD transmission, 188k miles. When I purchased this truck I knew of several issues, however, this apparently was not one of them. It seems when shifting after starting off under hard acceleration this truck shifts very hard into the next gear. If I ease off the accelerator just at shift point it shifts pretty smoothly. The next concern I have is what might be an overdrive issue?!?
When cruising about and the truck shifts into overdrive it randomly and apparently just seems to "sort of" disengage like it's slipping. It then will snap into gear or shift into a lower gear (like full acceleration passing) and just about snap your neck!! I have changed the filter and drained the torque converter (what a nice feature) and it still does this. The caveat is this:
When I am towing my motorcycles (light load 5x10 trailer and 4 dirt bikes) and disengage the OD on the column and drive, I cannot remember the transmission ever having the later two symptoms. It runs very well. It has been suggested since this apparently happens only when OD is selected it might be a solenoid. If so, any idea which one, and are these seviceable without tanny removal? No check engine lights so far. I have not disconnected the battery to reset everything and I have not checked for codes (although I just purchased an OBD-1 code reader). Your assistance will be greatly appreciated. Other than this one issue, the truck is amazing. Thanks very much!
I have a 1994 F-150 2WD, 302ci/4r70w OD transmission, 188k miles. When I purchased this truck I knew of several issues, however, this apparently was not one of them. It seems when shifting after starting off under hard acceleration this truck shifts very hard into the next gear. If I ease off the accelerator just at shift point it shifts pretty smoothly. The next concern I have is what might be an overdrive issue?!?
When cruising about and the truck shifts into overdrive it randomly and apparently just seems to "sort of" disengage like it's slipping. It then will snap into gear or shift into a lower gear (like full acceleration passing) and just about snap your neck!! I have changed the filter and drained the torque converter (what a nice feature) and it still does this. The caveat is this:
When I am towing my motorcycles (light load 5x10 trailer and 4 dirt bikes) and disengage the OD on the column and drive, I cannot remember the transmission ever having the later two symptoms. It runs very well. It has been suggested since this apparently happens only when OD is selected it might be a solenoid. If so, any idea which one, and are these seviceable without tanny removal? No check engine lights so far. I have not disconnected the battery to reset everything and I have not checked for codes (although I just purchased an OBD-1 code reader). Your assistance will be greatly appreciated. Other than this one issue, the truck is amazing. Thanks very much!
#2
#4
I am going to talk to a tranny shop and get some opinions.
#5
Hi. Thanks, and yes I did. I replaced the filter, gasket and supplied around 13-14 quarts of fluid (including converter). It shifts ok quite a bit, it just seems to be a random occasional thing that is extremely annoying. I still havent hooked up the OBD-I reader to see if a code was set. No check engine light as of yet. Will post any findings (short of a rebuild).
#7
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#10
Join Date: Feb 2008
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For the hard shifts:
Have you checked the accumulator springs? I suspect they have either been changed out (shift kit or separator plate kit before you bought the truck) or they are broken from age.
I have not had any issues with my OD so far (knock on wood) so I am not to sure about why it slips out of gear but it may be time for a rebuild as the overdrive is usually the first to go (at least that has been my experience).
Have you checked the accumulator springs? I suspect they have either been changed out (shift kit or separator plate kit before you bought the truck) or they are broken from age.
I have not had any issues with my OD so far (knock on wood) so I am not to sure about why it slips out of gear but it may be time for a rebuild as the overdrive is usually the first to go (at least that has been my experience).
#11
For the hard shifts:
Have you checked the accumulator springs? I suspect they have either been changed out (shift kit or separator plate kit before you bought the truck) or they are broken from age.
I have not had any issues with my OD so far (knock on wood) so I am not to sure about why it slips out of gear but it may be time for a rebuild as the overdrive is usually the first to go (at least that has been my experience).
Have you checked the accumulator springs? I suspect they have either been changed out (shift kit or separator plate kit before you bought the truck) or they are broken from age.
I have not had any issues with my OD so far (knock on wood) so I am not to sure about why it slips out of gear but it may be time for a rebuild as the overdrive is usually the first to go (at least that has been my experience).
No I have not. I am also not ashamed to mention I have no idea what a accumulator spring is or where it's located or what it would look like if it smacked me in the snoot! :-)
I will look it up and see if I can educate myself.
The problems listed are in the order of magnitude that they occur:
1. Truck hard shifts from low to second. Under hard acceleration. This can be duplicated every time.
2. The random slippage after shifting into overdrive. Once or twice a week (250 miles a week).
3. I am unsure if this explanation is correct, however, here it goes.
The truck rev's like it goes into passing gear (like full acceleration passing with old vacuum advance etc). This can occur when the vehicle is doing 65 on the interstate. If I ease off, it simply continues on as normal and runs great. It may happen again or may not.
4. These symptoms all go away when the overdrive is dis-engaged on the column. I have driven 200 miles this way towing with no events when it's disengaged.
Thanks for all of the feedback, keep them coming please!
Last edited by 94ford2wd; 06-10-2009 at 08:47 PM.
#13
hey i dunno if this helps you but read this TSB http://www.supermotors.net/registry/media/81709 its about the manual lever position sensor and oneof the symptoms is hard shifting. also i have a thread up titled "code 628", its a couple below yours, you might beable to get some more info off that
good luck!
-Aaron
good luck!
-Aaron
#14
One possible cause is that the separator plate is flexing, there is a repair kit or you can replace the plate. Don't wait you could burn up your transmission. I know I have a 2006 f-150 that failed and the dipsticks at monster transmission rebuilt three times and never repaired or replaced the separator plate. Found out when I had rebuilt the forth time in six months that this was the problem. Do Not Send your transmission to Monster Transmission for rebuilding, they will screw it up and will not fix it.
#15