Heaviness of the bier does not mean that the deceased was an evildoer
Question

If the body of the deceased feels heavy when it is carried on people’s shoulders at the time of burial, does it indicate that his bad deeds exceeded his good deeds?
Praise be to Allah.There is nothing in the teachings of our religion to indicate that. The most that has been mentioned by some later fuqaha’ is what is mentioned in Haashiyat Nihaayat al-Muhtaaj (2/466) by ash-Shabraamilsi:
Abu ‘Ali an-Najjaad was asked about the lightness or heaviness of the bier and he said:
If it is light, then the deceased is a martyr (shaheed), because the martyr is alive, and one who is alive is lighter than one who is dead. Allah, may He be exalted, says (interpretation of the meaning):
{And never think of those who have been killed in the cause of Allah as dead. Rather, they are alive with their Lord, receiving provision} [Aal ‘Imraan 3:169].
This was stated by Abu’l-Husayn in the biography of ‘Umar Abu Hafs al-Barmaki. End quote.
But the correct view is that this is not a valid sign, for there is no evidence that one who is dead is heavier than one who is alive. Therefore this is not proven either by the religious texts or on an empirical and rational basis, let alone that being a sign of whether the deceased had a good end or a bad end. It is not a sign of whether the deceased was righteous or an evildoer, especially since many people think ill of some of the deceased on the basis of such illusionary signs, and thus they fall into error and sin with no proof or evidence.
The following question was mentioned in Fataawa al-Lajnah ad-Daa’imah (9/86):
Some rational and mature-thinking people told me that they attended the funeral of a Muslim man who was very very light, and another who was very very heavy, and at a third funeral, when they brought him out of the house, the body appeared to float and move above the men’s heads. What is the Islamic attitude regarding these stories? Please note that those who witnessed that were trustworthy men of good character, who are unlikely to tell lies.
The answer was:
We do not know of any causes of the body being light or heavy except natural, physical causes, which is whether the deceased was small or large. As for those who claim that this indicates that the deceased was a good person if he is light, and that he was an evildoer if he is heavy, this is something for which there is no basis in Islamic teachings as far as we know.
As for the body moving on the bier, this indicates that the person is still alive and that he has not died, so the matter should be investigated and he should be examined by a specialist doctor to determine whether he is dead or alive, and they should not hasten to bury him until it is known for sure that he has died. End quote.
In Ahkaam al-Janaa’iz, Shaykh al-Albaani (may Allah have mercy on him) regarded the belief of some people that if the deceased was righteous, those who carry him will find him to be light and thus they will move quickly when carrying him as being a kind of innovation (bid‘ah). (Bid ‘ah no. 47).
And Allah knows best.